To GFI or not

[220/221]

what about near the bottom of nameplate where it says "connect only to circuit protected by a class A 50 amp GFCI"?

The way I understood it, it is/was connected to a 50A GFCI.

I have a 60 amp breaker from a sub panel to a 50 amp GFCI breaker disconnect,

Change the circuit to a 40 and it will comply with both labels.