Volume fluctuations?

New BB user here. On almost any set and style the bass drum is light for a few bars then heavy and clipping for a few bars then back. No pattern but a very noticeable difference. Setting or do I have an operation issue?

Found my stereo cable is bad :pensive:
Replaced cable and all is good!!! :sunglasses:

I file that one away. That would have been way, way down on my possible causes list.