I assume the recoil force is supposed to trigger for each fired output but even in small scale examples with a single output and slow fire rate, the physical force to move you back.
Not sure why it sometimes works or doesn't. Could be related to where you're looking at relative to the sector and where you are currently within it.
Thought at first it had something to do with too much force exceeding the maximum velocity, and it refusing to apply the speed then instead of limiting it, but that seems to be not the case or the values are just completely off and it overflows somehow. T1583 is quite similar in that case.