Unfortunately your phone won't allow the software to be rolled back via it's settings @KelvinGooner
Please try this which may help > Clear Cache Files from the phone's System Partition Section > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too.
And as a very last resort back up and factory reset.
If your still determined to want to roll back the software then look at xdadevelopers.com for relevant information.
I can't say this strongly enough > Please be very careful if you contemplate this.
Disclaimer 》
Using a Custom Rom / trying to use other methods to rollback firmware can bring about an unstable phone or it may not work properly if the process glitches or the wrong Rom is used. It may stop Samsung Pay from working if the procedure trips your Knox Counter.A person takes full responsibility if they perform this process and do so at their own informed decision. Again the process may trip Knox and may affect the Samsung Warranty. Samsung could levy a charge to put this right or deny support.
Instead I'd suggest to send feedback via your Samsung Members App and if possible visit a Samsung Experience Store or Samsung Service Centre for support.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "
