It's been going on since the last maintenance, sometimes I get CCed out of nowhere: I get on fire, shocked...
I do NOT have the special ammo directive active.
Anyway I brushed it off as some enemies having special ammo, until now: I just got hit by the flaming foam while in a firefight with hyenas.
And the foam was not on an area around me, it was litterlly just directly applied under my feet.
Usually when I get shocked out of nowhere, there's some sniper around who has a drone up. I don't remember a situation where I got shocked and absolutely couldn't find the cause - doesn't mean that such situations can't exist, of course.
I do occasionally get ignited, but like you, I attributed that to some enemies having special ammo regardless of directives. It only happens after getting hit, and often there is one particular enemy in a group whose shots ignite me. That enemy may drop fire ammo after getting killed, so it _looks_ like it is working as designed.
I can't tell if I have encountered the flaming foam outside of fights with the cleaners. There were a few situations where I didn't expect it, but it's pretty rare anyway and I don't have a perfect memory of those, so I couldn't tell whether this was working as intended. I haven't seen evidence to make a claim to the contrary either, though. From your description. I'm not sure if there is a connection between special ammo and flaming foam though.
Absolutely, the occasional fire ammo or the shocking turret I can expect. That's why I have not said anything up to now.
The problem is being CCed while in cover with nobody shooting at you: meaning that one single CC bullet is what hits you, nothing else.
As for the foam: there was no red circle, no AoE, just the single mound of foam appeared at my feet.