While playing minecraft on a xbox series S (Not sure about X ) anything that pops up on your screen ( getting a notification like an invite or message, talking or someone else talking in a party, or opening up the xbox menu) causes your minecraft to drop majorly in performance. This issue has been resolved in minecraft preview quickly however it has been in the current version of minecraft bedrock since vibrant visuals has been added.
MCPE-219679
Xbox s minecraft performance issues
Resolved
Duplicate
0
This is the fourth ticket you've created about this issue. As I said in each of those tickets, this issue is being tracked at MCPE-199201. Please do not create any more tickets about this issue. The fix for this issue should be included in the full 1.21.90 release.