Stuff reset during 1.21.1 launch

When I joined a server that I have alot of progress in, my stats and advancments where reset and every time I left and re-joined it teleported me to a spot in my base. It happened to atleast one out of two other players in the server. It happened right as 1.21.1 was released. I selected 1.21.1 because it didn't let me use 1.21