The tom arms are in charge now. ☠
This is a bad situation all around, but Sweetwater will take care of you. I have no idea what could be going on over there, other than the aforementioned tom arms seizing control, but it will get resolved.
Some people do it to mix up tom fills without changing sticking, or to break up descending/ascending fills. I do it because I use the 12" more frequently than the 10" next to it. I want the sound I use more right in front of the snare for easier access.