I am suffering with the same issue I have seen many others describe in Samsung Members and online namely the camera focus issue.
I purchased this phone mainly for the camera upgrade and I used to use it on almost a daily basis.
I had no problem with the phone from new but since the last major security update the camera is practically useless. I currently stand absolutely no chance capturing a spontaneous shot in anything other that 0.5 focal length. That seems to be the only focal length which will auto focus. I have to zoom in and out in hope the focus grabs but even if it does it can lose focus and start focus hunting again.
I have followed all the recommended fixes up to totally wiping the phone but after hours in contact with Samsung support they have now told me I have to take the phone into Samsung to be assessed before we can proceed any further.
This means the phone will be wiped, updated and I will be without it for several days. To say this is a massive inconvenience is an understatement as I use the device for banking and 2FA which are not easily setup again after a wipe.
The only thing that remotely makes me want to consider this option is Samsung have promised me the problem WILL be resolved one way or another.
Do I believe them? At this point no, not at all but unless I want to live with an expensive and useless (for my needs) phone have no choice but to go through with this.
What really annoys me is I am convinced this is purely a software issue so could be resolved with a software update but instead I have to jump through these other hoops.
I own many, many Samsung products (owned a Samsung phone since the S3 andcurrently 7 Samsung mobiles in my household) but this situation has really tarnished the company in my view.
Not so long ago this was an expensive flagship phone and I am amazed there seems to be so many people experiencing these problems and Samsung really seem to be ignoring the issue and hoping it goes away.
At this moment I don't think I'll ever purchase another Samsung mobile based on my experience with the S20 so Samsung you really need to up your game and proactively engage with S20 Ultra owners and fix these problems before people start to vote with their feet and go elsewhere.
I had also heard reports that the S21 has similar camera issues which is quite frankly astounding from a company of the size of Samsung especially as they seem to have learned no lessons at all from the problems of the S20.
This is a global leader in smartphone manufacturing and it seems they are making some staggering errors with their top phones right now.