Exporting at half fps with audio doesn't correctly export audio

What is your operating system?
Windows

What is your Shotcut version (see Help > About Shotcut)?
23.5.14

Can you repeat the problem? If so, what are the steps?
Yes. If I load an image sequence (or video) and add audio to it and export at the normal project framerate, everything works. If I half the framerate (for export, not the project framerate), the video is exported correctly at half framreate, but no audio and the resulting file has seeking errors and creates unpredictable seeking behaviour (varying from player to player).

Edit: Ok, this only seems to happen when trying to use b-frames… for some reason (HEVC codec with nvenc…)

I do not reproduce this in the 23.07 beta for the next version. I tested with both a video (1280x720p30) and image sequence.
There is a known bug in version 23.05 with NVENC and B frames on Window that was already fixed in version 23.06 (by defaulting it to 0, if you change it higher it does not work and seems to be a bug between ffmpeg and nvidia).