My self-hosted instance of Pixelfed had many database problems, actually.
I installed through YunoHost and had sooo many issues. Photos were not loading. Instances were not federating. I gave up and moved back to Mastodon.
The YunoHost installer needs some serious work. So does YunoHost in general. I recently moved over to RunTipi and I'm not looking back. Would love to have Pixelfed on TIpi so I can give it another shot.