Access denied importing on Ubuntu 20.04 due to Mono being upgraded

Sonarr version 2.0.0.5344:
Mono version version 6.8.0.105:
Ubuntu 20.04:

I upgraded to Ubuntu version 20.04 from 18.10 and it has upgraded my Mono which was 5.20.1.34

I had downgraded to 5.20.1.34 in order to fix the access denided issue but the repositort in this fix doesn’t work, I have looked and can’t seem to find another one - Permission issues after Mono 6 upgrade

Anyone know how to downgrade Mone on Ubuntu 20.04?

I installed Version 3 of Sonarr, happy days.