Auto transcription time code error unless using default timeline time code of 00.00.00.00

I am finding that if I make a subclip midway through an existing rushes timeline (I only need a portion of the footage to transcribe) and then use that new timeline to transcribe the audio, the resulting transcription throws any subtitles way down the end of the timeline and time code generated in the transcription is out by about 4hrs.

I found a work-around, but clearly a bug. If I modify the new timeline to start @ 00:00:00:00 before sending to auto transcription the resulting transcript seems to align the subtitles in the correct place. I can then modify the timeline start time code and everything is adjusted accordingly.