Hello,
I circled the ramps in red. The shorter one at project north is modeled as a floor and the longer one is a ramp element.
Spot elevations work no problem on the former but cause issues on the latter. when I hover over the ramp-ramp with the tool active, it shows me a 'not allowed' sign on my cursor.
I am not sure if it's a view range issue because i can place spot elevations at the ramp termini.

Thanks for any thoughts. i may just ditch the ramp tool altogether based on other comments from y'all .
Revit is amazing