Dash Cam

For my new 2024 Prius Prime, I had the Toyota Dash Cam installed.
It works fine with my iPhone.
But it steadfastly refuses to work with the Windows Dashcam Viewer. The latter successfully lists thumbnails of my trips. If I click on one, the player advances at the bottom of the screen, an audio track display shows sound recorded, the map shows my position as I was driving along.
Except...
There is no video or sound. If I go into the microSD card, there are numerous 50-second MP4 clips (presumably the viewer stiches them into one continuous video), and those MP4 play just fine with a Windows video player.
So it appears to me that there is a serious bug with the Windows software.
I have a almost-new laptop running an up-to-date version of Windows 11, so I doubt that the problem is with my computer.
I can find no support page on any Toyota server to look for advice or help.
Has anyone had the Windows version of the Toyota Dash Cam Viewer software working? Am I missing something obvious?