Here is a video of the issue.
It's only the tender, and it only happens in the curves. At first it was doing it in the exact same place every time, but once I started trying to figure it out, it would happen in other places on the curves. I disconnected it from the locomotive and pushed it around by hand, and it never did it. I set the locomotive at a slow speed and pushed the tender behind it so that the IR signal would remain linked, and it would do it. It also instead of going dead for a bit would play the whistle sound. Any ideas what the issue is?
Well, it took so long to upload the video (Like 30 minutes.) that I left the BB going around and around, and it doesn't do it anymore. So I'll let it sit over night and see if it does it again in the morning. I still want to know why it did it.