Command key modifiers issue

[Blady]

Configuration macOS 12.5, GTK 3.24.33 (build with jhbuild from gtkosx).
I get a key pressed event from a window and I display the key value (gdk_event_get_keyval), modifiers (gdk_event_get_state) and label (gtk_accelerator_get_label).
Here is the Key A with various modifiers:

Get_Default_Mod_Mask:   16#1C00001D#
     Key    -     Modifier      - Label
        97  -            16#0#  -  A
     65505  -            16#0#  -  Shift L
        65  -            16#1#  -  ⇧A
     65507  -            16#0#  -  Control L
        97  -            16#4#  -  ⌃A
     65513  -            16#0#  -  Alt L
       230  -            16#8#  -  ⌥Æ
     65511  -            16#0#  -  Meta L
        97  -     16#10000010#  -  Mod2⌘A

For the Cmd key, MOD2 and META are together set (10000010) thus the label function is puzzled and returns both: Mod2⌘A.
Is it a macOS issue in firing both MOD2 and META?
Is it a GTK issue in gtk_accelerator_get_label?
By the way, with option / alt modifier, the label function returns the macOS character corresponding to A (⌥Æ) and not ⌥A?
If this post is off topic, please indicate where may I post.
Thanks, Pascal.