FPP 6.x Debian MiniPC - Virtual Matrix issue

[Sobal44]

Hi Guys,
Regarding lack of the RPi on the market, I install FPP on Debian 11 by FPP_Install.sh on small PC to use the virtual matrix on my Christmas decoration.
Installation pass well, all is installed and configured, all date from Xlights go to FPP, but Matrix don't work like suppose to. Test mode on the video from attachment its in cycle RGB-All-None
Output configured as resolution 192x108
Please let me know what i can change to make it work,
how to go to more advantage options what I saw on someone screansshots?

[dkulp]

With some of the new video drivers and such in Linux, if they don't like the resolution that we try to set via the old framebuffer API's, they just don't do anything.   At some point, we'll need to move over to the newer DRM API's, but it's a bit of work.    Anyway, what MAY work is to set the resolution to 1920x1080, then in the "Pixel Overlay Models", create the appropriate framebuffer model with that size, but then set a "Pixel Size" of 10.   That would get the 192x108 virtual model size to use for the virtual matrix.

[Sobal44]

DKulp,
Thank you for fast answer, 
but this suggestion not help,
instead of RED, green, blue screen I have just near white vertical straps,
Could you let me know where is located old framebuffer API's i would like test some changes.
Any other suggestion how to fix it ? Christmas are soon, i don't want to miss projection of virtual matric in my decoration.

Regards
Mateusz

[Sobal44]

what about if i will downgrade a graphic driver? or remove it completly ?

[Sobal44]

I'd be very grateful for any suggestions I can work on.