This is the 4th post relating to this issue as the previous posts have not been followed up.  

Based on advice from @PM I have tried all the standard fixes including a clean install which did not help with the Panning issue.  

I then did a clean install and reverted to 2020 SP0 and DS 2020 works as it should. I then installed 2020 SP2 again and the Panning issue returned. So, for me the issue relates to SP1 & SP2.  

Is this a known bug - how do I report it formally?