What is the problem?
I've been using OctoPrint for a couple of years with no problems ; only problems I had were plugins problems. But now it seems it's a problem with OctoPrint, related to networking.
I recently rewired my home network. Until then, I was using a PiHole with its DHCP server enabled (and static leases). I removed the PiHole (for now) and reactivated the DHCP on the DSL modem/router ; I always use static IP leases. Internet works fine, TV and Netflix work fine, the local network works fine, but not OctoPrint ! The static leases are the same (IP = 192.168.0.28 since the very begining, and it never changed ; the 3D printer is 192.168.0.28, period !).
When I power the OctoPi ON, on the local display (a 7" touch display), I get a "The OctoPrint server is currently not running" screen. Hitting F5 on a keyboard solves the problem...
The weird thing is that if the OctoPi is NOT connected to the LAN (cable disconnected), OctoPrint starts as usual. If I reconnect the Pi to the network and reboot, the problem is back.
It seems something is slowing octoprint service down so Chromium loads before OctoPrint completed its loading. I can't understand why.
After deactivating the modem/router DHCP server and reactivating the PiHole, the problem disapeared...
But before I plug a PiHole into my switch (one year or so ago), OctoPrint was working flawlessly.
What did you already try to solve it?
Nothing relevant as I don't understand what's happening.
Disabling anonymous tracking has no effect.
Adding a line with "service octoprint start" before the chromium-browser call in "root/etc/xdg/openbox/autostart" gives a BSOD (black !). (I use TouchUI and it comes with openbox window manager). Disabling the TouchUI UI has no effect. Disabling the TouchUI plugin has no effect.
Reactivating the PiHole + its DHCP and deactivating it on the modem/router solves the problem.
Logs (syslog, dmesg, ... no logs, no support)
octoprint.log shows no error ; 4 seconds between the first line and "user logged in" ; what other log files should I look to ? I'm not a Linux specialist and have a very basic networking knowledge !
Additional information about your network (Hardware you are trying to connect to, hardware you are trying to connect from, router, access point, used operating systems, ...)
Reflashing the SD card with a known good backup image (8 of august) does not solve the problem.
What could do or need OctoPrint that has a blocking / slowing effect ???
I had a look to the queries in the PiHole Query Log Page, when starting, OctoPrint is connecting to Google, googleapis, github, and octoprint.org, and gets quick anwers (with PiHole DHCP being in use ; didn't test with the modem/router DHCP).
Forgot to say : I always use the same DNS, primary and secondary, from my ISP. (of course the DNS for the DSL modem is set to the PiHole IP when it is used as a DHCP server, and the PiHole DHCP is deactivated if I use the modem/ router one).
Really weird issue.