Here is my situation and I need some advise!

I'm USIMG graduated from a not well known medical school on an island. Completed my residency training at an University program. Completed my fellowship at an University program. Licensed. DEA registered. Board certified. Everything was fine.

I interviewed for several jobs and had several offers. Decided on one opportunity but later told that they had trouble verifying my medical school credential. So that fell through.

Anyone had similar experience? Medical boards didn't have any problems and I don't understand why this group had a problem.......

Advise?

this can be another way, the other way is to sue them for discrimination against you, since they are not a licensing entity and you are fully board certified and licensed by the proper authority, as you mentioned.
if the ECFMG certified you and the medical board, the medical group has no say in that, unless they have a very ligitimate reason, upon which they refused you working with them otherwise they are discriminating.