I've noticed a similar thing watching on my PC (Firefox browser). It doesn't go to black, but a few miniutes before the end of the episode the picture freezes for a few seconds while the sound continues. I also noticed it last week when I watched Lucifer.
Peacock Original Series "One of Us Is Lying" to Launch Thursday, October 7
Episodes 1-3 will drop Thursday, October 7, episodes 4-6 on Thursday, October 14, and episodes 7-8 on Thursday, October 21.