I don't think it has anything to do with NTP. Here's what we know:
Pi-hole is working for all clients
pihole -t shows activity from all clients
The Web interface only shows two clients
So Pi-hole is working, but the issue seems to be with the Web interface, so I still feel like it's cache. Do you have a different device to try to access the interface from?
I have tried multiple browsers on different machines and it is the same for all. A reboot of the system and everything works fine, then something triggers the web interface to fail. PiHole keeps working but web interface shows 2 clients and 0 ads blocked.
So logically I think some CRON or other scheduled job is causing this. I will see if I can shed anymore light on monday
Dave
I have reconfigured my rtc and hwclock (removed fake-hwclock) after doing some research on how to install rtc on pi. After doing this I now get no initial grace period on bootup where everything shows correctly, stranger still I only get 1 client (localhost) and 2 queries on debian timeservers.
I also uninstalled pi-hole and reinstalled with no joy. Very odd..
My localhost and one of my phones. It may be worth mentioning I am running UniFi controller on there as well.
I would say I have at least 10 devices using it has a DNS server but the queries seem to be from when I originally set up the router and since the upgrade nothing is updating on the interface.
I have tried that and tried accessing it from every different device I have that has a web interface. I've cleaned the cache on the pihole and the devices trying to access the interface. The admin console still shows the same statistics 1.7% Blocked, 2018 Total queries etc. on all devices that have tried to access the console. The only thing that seems to be updating is the CPU and Memory indicator.
I don't know. You can try the nuclear option (this will wipe out any customizations you have in the Web interface); it fixed an similar issue for someone else.
I'm not a huge fan of it, but it may get you up and running since we don't really know what the problem is.
@FredsFred I solved this for my system by doing a clean reinstall. I uninstalled pi-hole removed dnsmasq and lighttpd. I then went through deleting all folders and files related to pi-hole , php, dnsmasq and lighttpd including logs (important as just purging did not work for me). Then reinstall pi-hole. I appreciate this may not be practical for you as other systems may rely on these dependencies.
Hopefully you will find a good solution.
In my case my best guess is that I had a bad timestamp from badly configured hwclock or corrupted file after log was flushed. These being the only two items of interest on debug logs I found.