optimal solution found, but a constraint is actually not respected

[nibu147]

I'm using cbc 2.10.10 through pyomo. For a quite simple MILP problem (less than 200 variables) I get the "Optimal Solution found" condition, but then if I check the constraints fullfilment with the found optimal solution, one inequality constraint is not respected by a value of 120.

Any idea how to deep dive this?
And what could drive this inconsistency? (maybe numerical issues?)

Thanks!

[jhmgoossens]

Can you provide an export file of the problem?