Yes, it is unfortunately an issue with that particular card. The NVENC encoders in FFmpeg were updated to a newer version that has support for HEVC B frames, and it appears that setting defaults to enabled on all cards even if they don’t support it.
HEVC B frames are only supported in hardware from 7th gen (1650 Super) onwards. For older cards, you’ll need to provide -b_ref_mode disabled as the other poster suggested.
