Hello.
I have an existing ticket in A class (discounted first) from IAD-FRA-CDG on LH.
I was interested in changing it EWR-MUC-CDG to experience Allegris first with the appropriate additional collection.

When my agency tries to exchange it within the current PNR they get A0. When I say this I mean within the current PNR pulled up in Sabre.
When they pull up availability in Sabre as a fresh record with the PNR not open, it shows A1.

And yes, they are pulling up EWR-CDG all the way through each time.