We consider that if the classical vacuua of a theory are degenerate then each of them can be non-invariant under one or more of the symmetries of the Lagrangian. We can choose one of the vacuua and construct our perturbative QFT around that vacuum. Via choosing a vacuum, we spontaneously break the symmetry and our perturbative QFT constructed around the chosen vacuum would have this (spontaneously) broken symmetry and not the original symmetry of the theory we started out with.
However, in principle, there would be instanton corrections to the classically obtained degenerate vacuua and the degeneracy would break and we would, in fact, have a true vacuum which would have the symmetry of the full theory. So, it seems that if we add the non-perturbative corrections, the spontaneously broken symmetry should be unbroken. However, this seems strange because this seems to suggest that non-perturbative corrections won't just change the results of perturbative calculations by tiny amounts but, rather, would qualitatively change predictions such as if the gauge boson should have mass or not. Or am I mixing non-perturbative and perturbative results in a naive incoherent way? If so, exactly how do we reconcile the two views? Or do we even need to?