After installing the latest update on my s21 ultra Tuesday morning it has completely killed the touch screen on my phone making it completely unusable. After trouble shooting online I took it into the store so they could use a Bluetooth mouse to back up my data to another .device.
Since I am out of warranty I've been told the only way they will fix it is with a chargeable repair and quoted me £300.
I find this completely unacceptable from samsung as they have essentially uploaded a virus to my phone then told me tough luck when I want it fixed.
EDIT: My phone was a refurbished phone which possibly had a new screen on it. Most people seem to that the update has problems with some non-samsung screens causing it to become unresponsive although there are a few people with new phones and screens experiencing the same issue.
It seems the only way to resolve it is by paying for a new screen (if you're outside of warranty) or installing the old 6.0 firmware (which will void your warranty). There is tutorials on YouTube or XDA forums if anyone wants to have a go.