We didn't get One UI7 beta yet. I think it will take more time.

Check for software updates. If available, please update. Otherwise, wait for some time as it might get resolved on its own.I too faced this type of problem on my previous galaxy phones, but after some time, it's got normal on its own.

Did you install One UI6 beta on your phone?

Then turn off "Use volume keys for media" button. It might work.

Hi Astha, I think it was happeining due to back case, as it might be pressing the side mounted button.... Plese check it once.