Fire - OSU Operational Support Unit

I have taken a punt and acquired the OSU (as I want to swap out the HazMat Unit has it requires more staff that the CBRN Unit)
It appears it is not realistic to the UK, but that is a separate issue, after all it is a game and not a real-life simulation

The requirement is HazMat training
However, it comes up as no staff and I cannot assign staff
I then acquired a second unit, but it has the same issue
I have three spare HazMat trained staff, and my plan was to assign one to each of them

Have I missed something?

Quote from renalmedic

Have you bought an OSU pod? Staff can't be assigned to them.

With those, its staff in the Prime Mover that need the relevant quals.

Both one of each, and they are both none / no staff