Funding problem - salary scale - CNRS
You find yourself in a tricky situation.  Universities often try to establish equity among grantees, regardless of whether a funding source could in theory pay higher or lower salary.  The way I've seen others deal with this is through a preemptive negotiation with the university. The scales tip in their favor, because you'll probably apply anyway, but I've seen some wiggle room on salary.  But after the fact would seem unlikely. Worth a shot. But, if the granting agency in good faith believes you are making X compensation but you get Y, they might not be happy about it. If you ask your granting coordinator whether you should inform the agency if the discrepancy, it might get some attention.