Hot damn! I did try the manual iommu=pt commands and got 6.10.2 up and going for the last couple weeks. I was holding off on the 6.10.3 update pending verification that they'd fixed this issue.
Handy little gem! I did notice that after a stream is finished and/or user is logged off, on the Dashboard, the section still shows the active user(s) with a playback well exceeding the length of the stream. IE: A TV show with 43:15 runtime, the user has logged off ages ago, and the dashboard still shows as logged in, playback going on at 2:13:18 for the 45min show...