I got the achievement "adventuring time" without doing anything

Well so I joined the World and got the normal ressources and then suddendly out of nowhere i got the achievement "Adventuring Time" as my 8. achievement. This normaly takes hours to get and I don't know how it happened. And it's not like i got all the other Biomes through other worlds, 'cause this is my first world on Bedrock. I mean... i'm not complaining or anything, i just got an extra skin customization possibility, but it should be fixed.
Thank you