Inspector told me to match breaker size to appliance
The usual setup is:

Large breaker, matched to wire size, in the main panel.
Wires (protected by breaker) to a subpanel
In the subpanel, a separate breaker &amp; wires matched to each appliance.

GFCI is both code and critical life safety for hot tubs. The wonderful thing about GFCI protection is that it can be at almost any level - breaker in the main panel, breakers in subpanel, combined with receptacles. You generally don't want to (if available in that size) use a GFCI as your actual main breaker, because then power to your whole house would go out when there is a ground fault, as well as some other possible problems. And in the case of a hot tub, you don't want to put the GFCI any farther than the subpanel for a bunch of reasons. Since you already have a 50A GFCI breaker, you can go ahead and use that for the feed to the subpanel and you don't need any GFCI breakers (with their sensitive electronics) out in the subpanel.
32A for one appliance would normally get a 40A breaker. If that is really two loads - e.g., heater 24A, pump 8A (making up those numbers) then you would have 2 breakers - 30A for the heater, 15A or 20A (since that is normal for most small loads in the US) for the pump. You would also have either a shutoff switch or, often easier/cheaper, a main breaker in the subpanel which could be any size (since the individual appliances are protected by individual breakers and the subpanel and its wiring are protected by the breaker back in the main panel). The subpanel can have additional circuits - e.g., a separate lighting circuit, a convenience receptacle, etc.