I have Dell 7540 with NVIDIA Quadro RTX 3000 + integrated GPU.

I need to disable the integrated GPU and use only the Quadro, because otherwise the switchable graphics makes problems in Linux and I'm not able to get any proper drivers for that (single dedicated GPU should work just fine).

I'm pretty sure, when the notebook was new, there was a menu in BIOS "Video / Switchable graphics" to enable only the dedicated GPU. But now, the menu is missing and I can't find it anywhere.

Recently, the notebook has been repaired because of some PCI degradation error, i.e. the whole motherboard and GPU was replaced for new parts and BIOS upgraded to 1.10.2. I tried to downgrade BIOS to 1.9.0, but the menu is still missing.

Any idea why the menu can be missing? Can it be caused by BIOS upgrade or by the replacement of the parts (even for the same type)?