Same problem, it's ridiculous, that problem will last longer than the old Minecraft Legacy Edition, I think they should make a microtransaction to fix all the bugs with flash speed and for good reason.
Hello, and yes, the problem persists, and with all due respect, they are taking a long time to fix the bugs, I don't know if they want us to pay to fix all the bugs but I would do it since they are taking too long, I even think they forgot about the texture and audio problems in the mash up pack, especially the Halloween one.
Several mash up packs have this problem, the only places where the music can be played is in the plains, I think there is another biome that also allows the mash up pack music to be played