YouTube uses recognition software that scans the music in your video to see if you are using copyrighted material.
Bensound's music tracks are not registered in the YouTube content ID so:
You shouldn’t get a copyright notice when using our music.
If you credited us or used one of our paid options and receive a copyright claim, it is either a "false positive" (the software is wrong) or someone has fraudulently registered our music.
Anybody can register music to the Content ID. Even if you don’t have a label, you just have to create an account on a platform and upload the file. The consequence of this is that anybody can actually upload a musician’s music and claim it as their own work.
There are solutions that YouTube could implement: