Short status update: My Lychee Photoalbums are since some weeks down.
The reason is that I finally migrated my horribly outdated Lychee instance to the recent container, which for some reason won’t work on my subdirectory. It can be a simple stupid configuration mistake I’m too blind to see, but since I could reproduce it on my workstation as well, I filed Issue #945 for it.
Since this is fixed, it unfortunately doesn’t work.