2019 user here, I now have 1 item back in my already read list
I don't know if there is a pattern to when they are restored but this could be the first one I completed, I dont remember.
I had probably 500 items combined in already read, reading and want to read so I will try to write an update if the number goes up.
Note: I have not been re-adding anything to any of my read statuses, so I can't answer if that will affect the restoration

Do you guys think the downtime could have something to do with making a backup of the database? It might be wishful thinking but if it was some kind of maintenance? I hope that is why. Or upgrading security?
I am thinking it has something to do with the database because of the now slowly reappearing data, any thoughts?
Hellooo news here:
https://www.mangago.me/home/mangatopic/21080691/
Site status here:
https://www.mangago.me/home/mangatopic/21082568/
It was maintanence and during it one of the data discs got corrupted.