As we know that actually 3♣ is equal to checkback stayman, however whatever 3♣ is,I found it will be impossible to look for another major 4-4 fit even though I made many tries.
After 2nt ,the meanings of 3♥ is five card if you are holding 4-4 majors,you never rebid 3♥.
After 3♣,the answer from GIB will be only for 3 card responsive suit,ant it has nothing to do with another 4 card major suit.
So my conclusion is the GIB lost another major 4-4 fit after jump rebid 2nt .

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ing) tr. v. - Any bid made by bridge player with which partner disagrees.