Problems with Siri and playlists

Things got worse after the latest update (13.4.6) to the point where the HomePod wouldn't play anything requested. If I said "hey Siri play music", that would work and start playing a random song from my library. If I then requested the exact song it was playing, it would say that it wasn't in my library. So I called support and after about 45 minutes of troubleshooting (including resetting the HomePod again, and it acting very strangely) and escalating the the next level, we finally got it working by changing the language from US to UK on the HomePod and my iPhone (might not be necessary on the iPhone) and back again. Hopefully other people find this useful.

iTunes Match, thanks. I've seen several posts were people say that having different Apple ID accounts from your iCloud account can cause issues, (which is my scenario; been with iTunes since day 1), but it seems like the problem is not syncing of data, playlists, etc., since I can make Siri play the specific playlist by using some strange phrasing (vide supra). The issue appears to be something with the way Siri parses the request depending on how it is phrased. It's very strange.

I already submitted a bug report.

Still doesn't make sense that it's an iTunes Match thing because is does play the playlist if I make the request in an unnatural manner ("turn on shuffle for truck tunes"). But I can't rule that out for sure. Hence the bug report.