I too had the same issue. I installed dkms and then installed the Linux headers as per @Daniel answer. Then rebooted Ubuntu while remaining in full screen mode and it switched straight to the correct 16:9 resolution.
I too had the same issue. I installed dkms and then installed the Linux headers as per @Daniel answer. Then rebooted Ubuntu while remaining in full screen mode and it switched straight to the correct 16:9 resolution.