Not apologizing for carriers, some are really on the edge of lying to consumers, but you have to separate the 2 parts that make 5G different from 4G.

1. Higher frequencies: means higher throughput but also shorter range (you can literally block that signal with your hand). Only works if your phone supports these higher frequency bands, you have to be in areas where the carrier has deployed cells supporting those, and you have to be close enough.
2. Increased efficiency: mostly affects carriers, you likely won’t notice the difference. Basically means, areas that were congested before with LTE will now see less congestion.

I found most 5G ads infuriating. If you know the tech, you understand whats going on and how they aren’t telling the complete story. If you don’t know the tech, you’ll think, “Yay, higher speeds.” Nope…

In general I recommend checking protondb.com if you’re having issues with any game on linux. Lookup the game and scroll past the steam deck entries. Often somebody has posted a solution there.

I your case, switch to Proton experimental and use these launch options:

eval $( echo “%command%” | sed “s/Launcher/LariLauncher.exe’.*/bin/bg3_dx11.exe’/” )

It switches the game to launch the dx11 version. Alternatively, rename bg3_dx11.exe to bg3.exe or change the game from vulkan to dx11 in the launcher (if that can be done in the launcher). Vulkan is known to crash for some on Linux.