Just to clarify, the error you are seeing in the firmware updater and privacy settings are because your motherboard does not support UEFI, and instead uses legacy BIOS. There is no way to fix that without upgrading your hardware, and it shouldn’t be related to your issue, but it may be an issue for anticheat in certain games.
On an unrelated note, you should really upgrade your motherboard and CPU if you have the chance, as those will be massive bottlenecks to performance. Your GPU is way overpowered for those components, so you aren’t getting the most out of it. But that likely isn’t related to the issue you are currently facing, I just wanted to mention it if you have grievances with the performance of your current computer.