I loaded my backup to 2020.01-01, library and all settings etc. are back to what they were.
All still golden, no stutters or blackouts still.
I’ll give 2020.03 a go tomorrow and report back. Now that I have a install and backup ready that is confirmed to work I feel a lot more willing and confident to experiment some 
This is the same issue @ac16161 reported.
I am still working on it.
Thanks for your feedback, this is useful.
Ok, then I’ll hold off on updating? No problems, glad I can help!
If you give it a day, I can give more precise instructions on how to upgrade so we can isolate it to a more specific set of changes. I’m pretty confident that if you just upgrade to March again you’ll have problems.
Cheers
Great, just let me know when you’re ready.