I've been facing a similar problem to yours, however in my case selfoss occasionally presents the right interface. So, I just refresh the page till I get a correct result.
I'm running it under a heavy-loaded Raspberry Pi and my best guess so far is that the machine does not answer in time, and therefore we end with a crippled interface.

Nevertheless, I'll be monitoring the thread to see if someone else has a solution to these issues.

By the way, my config uses Lighttpd and sqlite.

Regards,
Mnl