Hey there and welcome to the Samsung UK and EU Community Forum
This sounds to me like you selected to withdraw from the beta in the Samsung Members App but then failed to complete the full steps to leave?
If so, you will need to complete the full steps to leave beta and then you'll be able to move to stable.
We strongly recommend in here that signing up for beta should not be for your main device and that you accept there are risks and possibly bugs that may cause issues for a while until fixed.
Beta is not the way to get the latest version early.
I am not employed by Samsung nor do I receive any remuneration as a Samsung Members Star.
My device is an S25 Ultra.