Thanks again, I've given that a try. Two minutes before my show is scheduled, I heard the disks spinning up, but nothing showed at the m3u link http://localhost:8409/iptv/channels.m3u
I didn't make a new playout, but I did refresh it. I'll try with a new playout and if that doesn't work I'll just wait until yourself or someone else figures it out.
Part of the problem is definitely settings not being properly saved at times, but at this stage I think I can rule that out.

Edit: oh, the episode at 7:30 played and startled me 😄
Now I just need to get this to happen on the correct days.