I've been running Pi-hole on a Raspberry Pi for a while and have started moving apps running on there to Docker on an Intel NUC (running Ubuntu). I've managed to get everything running OK on there apart from Pi-hole.
I'm using @diginc's Docker image from GitHub - frenos/docker-pi-hole: pi-hole in a docker container. After starting the container it seems to work OK at blocking ads, and the logs shown in Portainer and pihole.log don't appear to show any problems (as far as I can tell), but once the Web UI has loaded it doesn't show any details for Total Queries, Queries Blocked, Pi-hole's Query adjusts etc.
GitHub - frenos/docker-pi-hole: pi-hole in a docker container is a fork of my image that seems pretty far out of date. I've dropped the alpine image all together and only support the debian one now. I didn't think this error was possible on such an old image so I assume you meant my actual image (diginc/pi-hole:latest) not frenos's fork.
To summarize what I've gathered are the most common fixes for this problem:
Missing dnsmasq.conf log-queries=extra line
if dnsmasq/FTL ran without extra log queries, clean up both the FTL DB and pihole.log to get things rolling again
Can you re-confirm you do all 3 of those steps?
I would suggest running the latest version of my fork and clean up your volume data completely. If that doesn't work the debug steps for logs missing are typically to:
look at the pihole.log to see if dnsmasq is correctly recording queries with the right format
see if FTL is reading said logs into it's database
#2 can be accomplished with my newest image using the FLT_CMD being set to 'debug' as an environment variable.