During a duel, the music that plays is supposed to remain unchanged until either a Pokemon's affected by a status condition (until that status condition's cured, after which the normal music resumes), or until a player's down to 2 prizes.
However, the duel music seems to almost always randomly change to the music that's supposed to only play when a Pokemon has a status condition, and it will then continue playing that until a player's down to 2 prizes. 1 example that seems to trigger this bug often is when an active Pokemon evolves.
Thank you for reporting this possible issue.
The subject seems a little too specific to be investigated on the forum.
I believe that it's best to submit a ticket to our support team with all the detail you can provide so that they can investigate this further.
To do so, please use the link to the support portal in my signature.
Aside from that I've forwarded your feedback to our development team and edited the title of your thread to make it more descriptive.
Pokémon TCG Online Moderator
For more help please visit the Pokémon Support Portal to submit a ticket.
Prior to posting in the forum, please check out the forum rules.