I have no way of fully reproducing it regularly, but at times it will play the collection sound after load screen.

Using minilist

Version DF-3.10.5

Update, it does it on zone transfer, going from Elwynn Forrest to Stormwind, or Westfall etc

Been having it as well, started happening within the last 24 hours or so - I noticed that when I switched zones the counter at the top of the minilist started counting up, so it seems like it repopulates the "database" for the zone, and possibly in doing so it will play the sound for any completed group in the zone?

If you open the main map and go to another zone and click the ATT Mini List button, it plays the music as well.

I keep getting similar with the Exploration (WIP) module enabled, I assume the sound after loading is due to the maps not being cached or similar. Personally I do think having this being exempt from the jingle to be best, although having it guarded behind an option would be excellent too.

I however am not sure if this was added after 3.10.3, as I am using Git

I believe this is due to ATT collection logic of Exploration which was recently added. This will probably be adjusted in the future, but for now I've made Exploration not trigger the collection fanfare in b8c53d8