This may not help anything but sometimes when I have been really frustrated with my BSR and the machine in general. I just will turn off the machine and let it sit for a while. Then turn back on and try again. I don't know why but this has worked a time or two, not always.
Diconnnect your BSR and reconnect it too.
Take out the bobbin and clean up the area and re-insert it.
I don't know what else to tell you.