This is a kind of major problem in S21 Ultra.

[alokawasthi9]

This is a shot of S21 ultra after beta update in 30X Zooming. 

[mayankjangid5]

I also clicked with 100x it was also like this ....i hve also s21 ultra

[MittalPuneet]

Same here and reported to samsung too.

[hemangshah]

Same here on 100x zoom

[IndiaBetaTeam]

Dear Samsung Member,

Greetings from India Beta Team!

We acknowledge your feedback.
However, we request you to please report this feedback on the Error section, along with the logs. This would help us analyze your issue in a better way.

The path to report error is as below:
Open Samsung Members -> Click on beta banner -> Switch to beta mode-> Beta feedback -> Send feedback -> Error report

In the meanwhile, you can perform the below-mentioned step:

* Clear camera application data.
Settings >Apps >Camera >Storage >Clear Data.

Thank you for being our valued customer.

Warm Regards,
India Beta Team

[JayRed]

This worked for me