The map card for the MMCTF23 in V5B has this information:
(https://s15.postimg.org/afl23qnsr/ctf-mapcard.png)
The only thing right with the music credit is that it was made by RushJet1. The song itself is actually Bullet Bounce (https://rushjet1.bandcamp.com/track/bullet-bounce) from his album, Adventures of the 2A03 (https://rushjet1.bandcamp.com/album/adventures-of-the-2a03).