Can't stitch 5K RAW content longer than 30 minutes

I'm slowly narrowing in on a virbstitch failure on long videos that I've been experiencing. I was testing out the flow, so made a long video (2+ hours), and that failed to stitch. So, I copied the contents of the Garmin 360 SD card to a disk (as shown on one of the sticky posts) and tried importing from there, and that failed the same way. I had been able to stitch a few smaller videos of about 5 minutes in length, so knew that at least something did work sometimes with my system. So, I made a copy of the data on disk and started removing the video files. The files are split up into segments of 30 minutes long (about 11GB each). This continued to fail unit I got down to just the pair of mp4s for the first 30 minutes ie the video to be stitched no longer spanned multiple .mp4 files.

After that, I made a recording of length 26 minutes, which I was able to stitch. This was all in a single pair of mp4s.
Then, I made a recording of 36 minutes in length. This one spans multiple files, for a total of 4 .mp4s, and this failed to stitch.

At this point, I think that virb stitch has an issue with video that spans across multiple files.

Has anyone else noticed anything similar?

I submitted an email to the support center over the weekend, so don't have a response yet.

Thanks,
Kirk