All Progress on a Server was cleared without any cause

When joining in a server, Portal2Elysium, all my items were gone and it said I was logging on for the first time. Dont know why it said this as I have logged on this server before on this account. When I checked my build plot, it said it was owned by Master67568 which is what I changed my username from. It wouldnt let me build on it because it said it wasnt my plot. I dont know why this happened but I think it was caused by me changing the username to my account and the server not knowing it was me. The new tag system for xbox i dont think is read by Minecraft so it added the tag of 4 numbers on to the end of my new username, Master6756 is what I set it as, Master67565173. Everything for my account was the same, my profile picture, my gamerscore, everything. I also posted this to the xbox feedback because this may also be a problem on their end too. Pls find a solution if possible, i dont want to lose all my progress on all servers.