Any updates on this Dave?
Still investigating this one 
Tonight my wife was watching AGT which started at 7 pm and ended at 9 PM. I guess she was time shifting it. At around 9:05 9:10 PM she mentioned that she can’t fast forward its jumping back to earlier in the show earlier than what the fast forward bar indicates. I could see on Plex Web client that it was still recording at around 9:15. I think it was post processing when this was happening. PMS version 1.19.1.2630 watching on Roku.
I see this behavior using a ROKU Ultra (W10 server Hauppauge quad PCI tuners, wired Gb connection) all the time. Time shifting has always been sketchy and there’s another thread here with more examples - Start Watching Recording in Progress from Beginning(Failing) - #972 by rakstr_sbcglobal_net
You may also notice that if you’ve been watching a station for an extended period of time and attempt a time shift it will go back previous shows and/or random spots. I used to think it was only while you were recording but it doesn’t matter. The behavior is the same whether the show is set to record or not…
This still happens in the current version of PMS.
