I can't get past that point. I hire any of the thugs that are supposed to break it open, the thug won't carry over to the next level after the loading screen. It is weird, because I was able to carry over the very first thug to the sewers with no issues.

Hi,

Maybe check out a walkthrough video of that section to make sure you are doing everything correct.

https://www.youtube.com/watch?v=8zw__qvV2UA

Thanks, but I already did my homework. But since we're at that:

https://youtu.be/8zw__qvV2UA?t=4m28s
At that exact point, the hired thug doesn't port to the new level. Sometimes he remains at the previous map (and no longer as a hireling of mine), and others he just disappears.

I asked someone about this bug and he suggested this:-

you need to make sure that the bot is close to the safe
and you need to give a action and then press the location with f
̲̅bind x key2
̲̅bind f +activate
̲̅so key2 is action key
̲̅and f is activate on the safe
̲̅the thug needs to be on the elevator before he press the button so it's moves to the next level