I have gone to Settings → General → Advanced → Shared clipboard and changed to Bidirectional. Also did the same for Drag'n'Drop and changed it to Bidirectional too.
However I am still unable to copy and paste from my Windows 10 desktop to my VirtualBox 6.1.2 which runs on Ubuntu 20.04.
I basically want to be able to copy and paste from my Windows machine to my virtual Ubuntu machine.
I cannot comment but when I used Windows 8, VM 5 and Ubuntu 18, I also had issues, and had to apply fixes, like:
Have you run these? Now I try with Win 10, VM 6, Ubuntu 20 like you, and nothing helps...
OK fixed also for me, but in another way:
Check for updates didnt show newer, hence I thought its the newest.
Installed VBox 6.1.8, replaced 6.0.22, clipboard works.
You could also SSH into your Ubuntu VM and right-click to paste into the console.