allegro.pl recognizes swapped user agent

[Nuc1eoN]

allegro.pl will block you if you are accessing it on linux (brave browser) from a Windows user agent (chromium). Also happens when I select Android, however I understand that this would be easier to detect..

When I boot up Windows 10, and enter with a Linux or Windows user agent I am not getting blocked! However upon selecting Android I will get blocked as well.

How do they detect that I am using Linux??

It seems like there is a potential leak of information.

EDIT:
Just one variable, but through deviceinfo.me I was able to figure out that my graphics driver clearly points to a linux driver:

AMD, AMD Radeon RX 580 Series (radeonsi polaris10 LLVM 18.1.8, OpenGL 4.6)

I wonder whether they are using this kind of information to detect a falsified User agent.

Any way to alter or block this string so I can test?