No it's a long standing bug that showed up around 2021 where songs were inexplicably stopping after 15s. Some thought account issues, some thought Apple Music was down, etc. etc.
I have them on select files. Stuff that I added to my library way back when that is matched. Some that are uploaded do the same.
Then there is also the long standing bug where Apple Music just stops playing. For whatever reason it doesn't load the song. You try and it just won't, forcing you to skip to the next song. It's insufferable and shows up in waves now and then.
You can get around some of the stalls by downloading the song to your device. It will play just fine then. It's not anti-piracy, Apple doesn't do shit like that. If they had proof of anything, they'd ban your account indefinitely and move on.
AM is not a good service I'm sorry to say. Yes the song quality is amazing and the recommendations are decent, but playing things, it's always been super super twitchy. Like if you look at it sideways it stops playing. I've been on it for 6 years. This is kind of known in the AM community.