Belmornes Path - auto failing since 2+ corpses spawn at the eastern gate

This is mission 9 of the main campaign, I go through and capture the first outpost and its fine, I start the second outpost finish it but then the narrator starts talking about a mop cleanup since I apparently let though 2 enemies. However I portcullis'd the area and cleared the Eastern Gate zone, so I check and its just 2 corpses spawning in at the Hero Gate, so I'm already at 2/10 fail limit without them actually making their way to said Gate.

I go to take over the next outpost, the count ticks up, and as I'm crossing the bridge and then more enemies just "slip" by some how, and I'm stuck waiting for the final wave and auto failing as a result. It's happened every time I've tried to beat the level whether its from my save or a fresh restart.

It's verison (v2.1.0f4) on Steam

Windows 10 Pro   64bit

8GB of Ram

CPU:  AMD Phenom(tm) II X6 1090T Processor

GPU:  Radeon RX 580 Series

Output Log:  output_log.txt

Save:  ....9 belmorne's pass lambs to the slaughter_20230410202327
9 belmorne's pass lambs to the slaughter....meta

That should be the save just before it happens.