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#Setup
Unbound Pi Hole running on Raspberry Pi 3 B
Your debug log shows your router to distribute its own IPv4 as local DNS server:
*** [ DIAGNOSING ]: Discovering active DHCP servers (takes 10 seconds)
Scanning all your interfaces for DHCP servers
* Received 300 bytes from eth0:192.168.1.1
Offered IP address: 192.168.1.3
DHCP options:
Message type: DHCPOFFER (2)
router: 192.168.1.1
dns-server: 192.168.1.1
--- end of options ---
This would suggest that you have pointed your router's upstream DNS servers to your Pi-hole machine's IP.
In such a configuration, your router would appear as Pi-hole's only client, and as it would aggregate DNS traffic from all your clients, it may well trigger Pi-hole's default rate limit at busy times and/or with a very large number of clients, contributing to your observation.
It also shows that you have enabled Pi-hole's Conditional Forwarding:
*** [ DIAGNOSING ]: Setup variables
(...)
REV_SERVER=true
REV_SERVER_CIDR=192.168.1.0/24
REV_SERVER_TARGET=192.168.1.1
REV_SERVER_DOMAIN=
This may also contribute to your observation, as this would close a partial DNS loop:
If Pi-hole would send 192.168.1.0/24 related requests to your router, your router would send them back to Pi-hole if it wouldn't know the answer, and then Pi-hole would send them to your router, and so forth, until rate limit or time-out kicks in.
To avoid both potential causes, you should configure your router to propagate your Pi-hole machine's IPv4 (and IPv6, if applicable) as local DNS server, provided your router would support that configuration.
You'd have to consult your router's documentation for its configuration details. Usually, that appears under a label of a LAN/DHCP kind of setting, as opposed to a WAN/Internet one for the router's upstreams.
Ahhh, i think i understand. I'll give it a shot later tonight. I'm not sure if my router (Netgear Nighthawk AX12v2) allows me to set the DNS option to all the clients. I don't recall a DNS option in the "LAN settings" or the DHCP settings only on the "Internet Settings" page, but i'll double check. I'd imagine this probably means I should move DHCP over to the Pi-Hole as well?
Yes if there is no option to set DNS servers in the LAN DHCP section of the router.
EDIT: Oh ps, I would change the order of enabling and disabling DHCP services!
First configure Pi-hole DHCP and enable it.
Check with below:
sudo pihole-FTL dhcp-discover
If that looks all dandy, disable the router DHCP service.
This because some routers re-initialise their network interfaces when changing network settings causing the clients to try and get a new DHCP lease while there is no DHCP service active yet.
And thus loose their IP details.
Including the PC from which you are changing settings.
To apply the new setup, your clients would need to renew their DHCP lease to receive the new DNS server (Pi-hole).
You can do that all at once by power cycling your router, switches and AP's.
When the clients detect network is restored, they will apply for a new DHCP lease and get one from Pi-hole including the DNS server.
In the end, only one DHCP service should be active on your LAN!
Oh I forgot an important bit!
If the Raspi is going to replace the DHCP service from the router, it should be configured with static IP details instead of a DHCP lease or static reservation.
A DHCP server (Pi-hole) cant supply itself with IP details via DHCP.
You can configure static IP details on the Raspi with below tool if you run a current Raspbian/Pi-OS release:
sudo nmtui
Network Manager Text User Interface
Thanks so much for that info. It seemed to make things much better. Everything ran smoothly for a a day or so, I was able to work without issue, stream some football and all that. However, something was up this morning. My GF was able to watch netflix on the xbox via wireless, but the wireless on my phone wasn't working so I logged into the web console and saw this error
"DHCP packet received on eth0 which has no address"
I did a quick google search and saw someone post about adding a line to /etc/pihole/pihole-FTL.conf. So i added that line "DELAY_STARTUP=5" and then rebooted the raspberry pi. Things seemed to work ok for a few minutes, the xbox was streaming netflix this whole time, no buffering but my phone still wasn't working. I tried to go to the console and it came up ok, and I was able to SSH into it, but after a few minutes it was like the connection was dead. I couldn't navigate the web console, the browser timed out and the ssh session timed out and I couldn't reconnect.
I rebooted again, and the same thing. Everything seemed to work OK for a few minutes but then the SSH and web session would just die out. But it was like it still had connection. The Xbox was working fine on the wireless, my work computer (wired) couldn't browse anything, but the weird thing was I had my AWS Workspace up and it didn't lose connection and I could browse the internet there.
I was able to reboot it again and run a diag log: https://tricorder.pi-hole.net/OgrYJ17W/
Hopefully that'll point to something, but after your initial suggestion of turning on DHCP on the Pi, setting the static IP on the Pi, and then disabling DHCP on the router things were working wonderfully until this morning. So far it's beeing working ok since i was able to log into this site and respond (about 8-10 minutes) maybe it was just a fluke, but just in case if you see anything else in the log that would help iron things out, that would be great! I really appreciate it!!!
Update….as soon as I hit submit on my reply it froze up again Or whatever it does. Couldn’t refresh on my phone. SSH session timed out browsers wouldn’t load any page. But the Netflix is still running just fine. 
Above sounds like the Pi is not configured with static IP details yet.
So after you disabled the router DHCP service for Pi-hole to take over, the Pi still has an active DHCP lease from the router DHCP service for the duration of the DHCP lease period.
Depending router, this is usually 12 or 24 hours and can be checked with below:
$ sudo pihole-FTL dhcp-discover
Scanning all your interfaces for DHCP servers
[..]
lease-time: 86400 ( 1d )
So after the lease-time expires, the Pi looses its IP details as it cant supply itself with IP details from its own DHCP service.
You can check with below one:
nmcli -t -f name con show --active | xargs -d '\n' -n 1 nmcli -p -f ipv4.method con show
If the Pi is still configured to acquire IP details via DHCP (the default) it will look like below (with "Wired connection 1" being my profile name for my network connection):
$ nmcli -t -f name con show --active | xargs -d '\n' -n 1 nmcli -p -f ipv4.method con show
===============================================================================
Connection profile details (Wired connection 1)
===============================================================================
ipv4.method: auto
-------------------------------------------------------------------------------
===============================================================================
Connection profile details (lo)
===============================================================================
ipv4.method: manual
-------------------------------------------------------------------------------
If the Pi is properly configured with a static IP instead, it will look like below with "manual" instead of "auto":
$ nmcli -t -f name con show --active | xargs -d '\n' -n 1 nmcli -p -f ipv4.method con show
===============================================================================
Connection profile details (Wired connection 1)
===============================================================================
ipv4.method: manual
-------------------------------------------------------------------------------
===============================================================================
Connection profile details (lo)
===============================================================================
ipv4.method: manual
-------------------------------------------------------------------------------
Dont mind the "lo" profile!
Thats for your loopback interface:
Below an nmtui example with 10.0.0.1 being my router and home.dehakkelaar.nl the domain configure in the Pi-hole DHCP service:
You can configure the default domain name displayed in the DHCP service settings.
Or "home.arpa", "internal" or "lan".
EDIT: I prefer home.arpa as its intended for this purpose and that name cant be stolen:
$ whois home.arpa.
[..]
contact: technical
name: Internet Assigned Numbers Authority (IANA)
[..]
remarks: This domain is administered as part of the .ARPA zone
remarks: management, described at https://iana.org/domains/arpa