Use expanded result of macro as parameter to other macro - c++

Question

There is a macro that I want to use that takes arguments in this format:
COMB(unique identifier, argument 1, argument 2, argument 3)
I want to create a wrapper for it that automatically generates the unique identifier. I found this answer that has code to generate a random ID, which I am using in my code:
#define PP_CAT(a, b) PP_CAT_I(a, b)
#define PP_CAT_I(a, b) PP_CAT_II(~, a ## b)
#define PP_CAT_II(p, res) res
#define UNIQUE_NAME(base) PP_CAT(base, __COUNTER__)
#define COMB_U(key, ...) COMB(UNIQUE_NAME(comb_r_), key, __VA_ARGS__)
// Using the macro
// The parameters are enums
COMB_U(KB_1, KB_2, KC_Y)
When I compile this I get a bunch of errors from inside of the COMB macro code like this:
‘cmb_UNIQUE_NAME’ declared as function returning an array
function ‘cmb_UNIQUE_NAME’ is initialized like a variable
As well as inside of the file with my code:
‘comb_r_’ undeclared here (not in a function)
#define COMB_U(key, ...) COMB(UNIQUE_NAME(comb_r_), key, VA_ARGS)
And a bunch of messages that don't seem to be associated with an error, like this one:
note: in expansion of macro ‘COMB_U’
COMB_U(KB_1, KB_2, KC_Y)
How can I fix this?
For reference, the source for the COMB macro is here: https://github.com/germ/qmk_firmware/blob/master/keyboards/gboards/g/keymap_combo.h