Using SRAM red 2012 chainrings with 10sp 1070 chain. It only happens under force like you said. Never had this problem with my old bike, then I switched the components over to a new bike. Could it be a FD adjustment problem?

Seems like the chain could not shift down in time and gets stuck between the gap of large chainring and FD outer cage

Also every time it happened I was under the trim mode

Any insight and help is greatly appreciated