Changed username and now can't get achievements for almost 40h

[Castior]

I got tired of seeing my old username in-game today, so I went to my profile on the website and changed it, but it didn't switch in the game, so I did some shenanigans using the /swap-players command and finally managed to get my proper username in the game.

However, now the game doesn't recognize me as being the person who played on the world for close to 40 hours and has thus locked me out of getting achievements until I reach 50% of the playtime in the world, which would require me to play for almost 40 full more hours, this is incredibly frustrating and I would like to know if there is a workaround so I can get my deserved achievements.