I had a similar issue, caused by me trying in vain to get OpenVPN running on my server, purging all VPN stuff got me back.
I ended up buying a GL-inet Mango and running Open VPN client on it.
Do you have VPN installed, i.e. is the server trying to route through TUN0, but it's not setup correctly or corrupt?
Yep, that worked.
I left it for about an hour with the log open an all sorts of stuff was downloading / unstuffing and happening!!
All up and running now.
Just be patient, it seems to be hung on;
[mod-init] Attempting to run Docker Modification Logic
[mod-init] Applying linuxserver/calibre-web:calibre files to container
But if you just leave it alone t sorts itself out.
So I was having issues trying to get this working, (nuked & re-installed 4 / 5 times)then checked the logs...
[mod-init] Curl/JQ was not found on this system for Docker mods installing
This error is triggered by lack of network on container start-up...
So I set Autostart and wait to 5 seconds, now it's pulling some archives and applying it to the image?
Will update if working. Seems to be stuck thinking about something.