Black Screen on Samsung S20

I have been reading all over about the issue with the black screen and the ar camera in Unity. I have the issue on my phone, and I do not seem to be able to get rid of it.

Is there some central source looking into this issue because there seems to be no consistent fix. Any that I have seen I have tried and it has not worked.

I don't want to update, Unity, it was working with this version. I can't tell what change made the difference.

I do not have ARCore selected because it requires me to upgrade Gradle, I tried that, it didn't work and next would be to upgrade Unity which I do not want to do

Unity 2019.4.17

Vuforia 9.8.5 

Galaxy S20

SM-G980F

Further to this I have tried a number of other things. I backed up the source and then upgraded to 2020.3.21 and Vuforia 10.2

Nothing changed.

I then tried forcing the camera on and this then disabled the webcam on the development PC. I commented out that command but it won't come back. 

I have seen this issue dates right back to 2012. And no solutions offered by PTC and any solutions tried have been flukes and do not work all the time.

I would assume that given this issue has been around for sometime, someone should be able to address the issue.

I do not have XR installed and thus have not installed AR Core as it is now depreciated by Unity. 

I did have the set the following line which was working fine

Vuforia.VuforiaBehaviour.Instance.enabled = true;

I was using this to turn it off when at particular screens.

I also tried opening a new screne and progressing from there, this did not work.