RB 7 - RPI3b+ - Shaders bug ?

[Space81]

Hi, first of all, THANK YOU.
I installed RB 7 ( i come from version 6.1.1 ) and i have a big problem: I can't in any way set up a simple global shader as I did before on 6.1.1, I also checked the global.shaderset = scanlines variable in recalbox.conf, but nothing does not see it, I have a rpi 3b+, thanks.

PS. I read about the same problem in the forum in the French section, but I don't understand what is the solution.