Seems you missed some changes to do in the 6.0.0 release notes: PeerTube/CHANGELOG.md at develop · Chocobozzz/PeerTube · GitHub
In particuliar, this part:
Directory on filesystem must be renamed from
videos/
toweb-videos/
to represent the value ofstorage.web_videos
- Classic installation:
sudo -u peertube mv '/var/www/peertube/storage/videos/' '/var/www/peertube/storage/web-videos/'
- Docker installation:
mv '/path-to-docker-installation/docker-volume/data/videos/' '/path-to-docker-installation/docker-volume/data/web-videos/'
(but you should check what else you missed)