So I thought I wanted to give an update in case anyone else should run into similar issues.
As mentioned in my post I did try several things including rebooting HassIO. I did phrase this as rebooting my Raspberry Pi but perhaps this is technically not true - I don’t know exactly what Restarting HassIo does so…
Eventually I power cycled my Raspberry Pi and while it didn’t solve the issue it did appear to address item 3 in my list of things that I had tried meaning I now were able to download the code via USB without experiencing any problems.
And after successfully having downloaded the code over USB I could subsequently download the same code OTA.