Basically, I did a solo run of FSC and when I got to the 1st set of wheel launchers I didn't
recall the Slag Walkers having spawned (I usually rush depth 24 so I don't take notice of much).
When I headed up to the Totem-room I noticed the wheel launchers didn't spawn. So, I got on the
party button and cleared the wave to further observe this without any annoyances. I then
invited a friend to make sure it wasn't a client-side bug and he confirmed he doesn't see
them spawned either. I then walked into where they're supposed to spawn and re-arranged a few
Totems to check if the Totems would still collide with something, but it seemed they (really) didn't spawn.

Having remembered about not having any interaction with any Slag Walkers from the 1st set of wheel launchers,
I headed back to see if they spawned at all. To my surprise, the Slag Walkers spawned. After killing the Slag Walkers,
I headed back up to the Totem room and the wheel launchers spawned! But the totems were stuck inside the wheel launchers which caused
the wheels to not be released and instead being destroyed by the totem that's stuck inside.
Having already defeated the Slag Walker beforehand and taking a few screenshots of evidence for this
bug report, I continued with the run.

I'm not exactly sure how this happened but I think it could be a trigger-related bug. I might've
gone Sonic-fast and the trigger didn't notice me or something. /shrug

The Imgur link provided shows my encounter of this bug, with each picture detailing what I am doing/showing.

https://imgur.com/a/oiyMD