I set up a Pi-hole with a BGW320-500 from ATT, I set the DHCP to enabled on the Pi-Hole. Turned off the DHCP server under my router settings. My network goes down either around 7am or 10am the day after setting up the pi-hole. I can't access my router settings or the Pi-hole web interface, restarting the pi-hole does not fix the issue, eventually after about 10-20 tries I am able to access my router settings and turn the DHCP server back on.
Expected Behaviour:
My network should block some ads and not go down everyday, I had it set up before and it worked as expected.
Actual Behaviour:
My pi-hole goes down along with my whole network, not allowing to me reset after.
Your log reveals that your router's DHCP server is still running along with Pi-hole's. Re-check your router and make sure the DHCP is definitely turned off. Then take your devices off and back onto the network to pick up the correct network info from Pi-hole.
A DHCP server requires a static IP address, usually to be configured directly on the host machine (i.e. not as a static lease in Pi-hole's DHCP, but by the host OS's network stack).
If your Pi-hole host had acquired its IP via your router's DHCP server instead, it may lose that IP in the absence of that DHCP server once its DHCP lease expires.
Without that IP, all clients DNS requests would fail subsequently, which would nicely match your observation.