Cannot join tournament (Wrong Rating)

For some reason for the past day or so I cannot join U2000 Blitz Tournaments. Lichess seems to think I am above 2000 even though I am 1800 right now. Screenshot below.

Why is this happening? Am I misunderstanding something?

You can have successfully entered the tournament)

You were rated 2021 in the past week, specifically 5 days ago. Wait for 2 more days and you will be able to join U2000 Blitz arenas.

This is in order to prevent sandbaggers entering tournaments.

Ah, didnt know that's how it worked.

Thank you

@MarkHC It is a security mechanism, as there may be users who download the classification purposely just to be able to qualify in some tournaments. Thus, it is necessary to have at least 7 days below a classification. This was a brilliant developer idea. Hugs.