MacBook Pro keyboard lag on Big Sur

I bought a brand new 16" MacBook Pro 1 TB on Tuesday, When I am typing it seems to freeze for a split second then carry on. So on Wednesday I went back to the apple store I bought it from and they decided to give me a replacement. And the replacement faces the same issue. So I took it back on Thursday and they told me to reinstall Big Sur, still facing the same issue so yesterday (friday) I took the replacement back to Apple and got a refund. Thinking it maybe a issue with the batch at the store I was at, I decided to buy the same model online and that has came today and has exactly the same issue.

On the other macs I was running Big sur 11.4 but on this one I am running 11.2.3 as the lag isn't as bad.

I have tried doing a SMC and PRAM reset but still no difference, and also when I got the replacement I set up the computer as a new machine and manually transferred all my files over.

Can the 16" run Big sur? My 2019 iMac runs it fine and that only has an i5.

Any suggestions would very much be appreciated!