Somehow they magically know your details in a lot of places such as France and Spain
I had the same experience recently routing VFR through Italy / France.
Filed VFR plans for all legs. Italy wasn't great, first couple of handovers they knew who we were, after that despite being told our next station had our details they didn't. Approaching the French FIR it was the equivalent of a freecall despite being told otherwise. Then on entering the French FIR the ATCOs we spoke to had our details and all handovers were smooth and babble free. French ATC an absolute pleasure to deal with.