One issue was in prod.secret.exs:
config :pleroma, configurable_from_database: true
The path in AdminFE was still /var/lib/akkoma/.... and putting it to the following resolved the issue:
Now the previously uploaded media before the switch to Docker works again. However uploading new media is still broken.
When uploading new images, they are not displayed on the FE and cannot be pulled remotely due to their link being
https://media.brotka.st/proxy/{some_chars}/{file_hash}.jpg
However, they are available under
https://media.brotka.st/media/{file_hash}.jpg
Edit 2:
After several rounds of experiments, this seems to work. Important final slash?
