GPU not detected by Brush accelerator

Hello everybody, this issue is not new to you, I read about everything in this place, there were good hints, but not for my case. 

My PC is a rather old Acer Predator:
4 cores 3.60 GHz

The thing was working for a year, but rather slow with brushes. 

So I installed a GTX 1550 with OpenCL 1.2 and the latest driver

But the painter doesn't detect it. 

What I did on recommendation of the Painter Support:

  • uninstall, delete temp, reinstall, make Win update, reason: "to repair the Visual C++ Redistrutable 2019"
  • nothing regarding *A less-powerful GPU may not actually outperform the CPU in a user's system", because my GPU is not greyed, but it's detection error
  • nothing regarding "There must be a issue with the system so please check if the system requirements..." because Painter confirms that my system MEETS.

So, here I am. I'm already considering resetting the workspace but haven't dared yet. 

Is there a nice friend having a recommendation?

Best regards from the Emmental (Switzerland)