Try a new user on the VM that has the problem …
I tried to return to open source on my machine (not VM) but with no difference, the problem is still there. So it is not Nvidia either. I have 2 versions of XFCE on it, stable and testing branch. Both have it.
Ok I’ll take a pause for now.
Made a new XFCE install, installed Nemo (indeed it doesn’t drag as much from Cinnamon as i previously thought), i made the updates … no issues. That means, IMHO, there is something in ~/.config and/or ~/.local that got funky in the user you experience this problems.
Good news, found it ! bogdancovaciu, you were right.
I noticed that leaving my mouse long enough on the selection “new document”, eventually it appear after 5 - 10 seconds. I was experimenting with new themes and icons sets. The “modèles” folder contain about 50000 files. As soon I moved them to another disk, the problem disappear. That solve Nemo too. So beware …
So my apology to the Manjaro team. It was not there fault after all.
Thanks to everyone helping.
Glad you sorted out. Indeed 50000 files is a lot.