I have 2 FN layers, activated by keys A and B
When A is activated, pressing B triggers ACTION_MODS_ONESHOT(MOD_LSFT)
When B is activated, pressing A triggers ACTION_MODS_ONESHOT(MOD_LSFT)

So in theory, regardless of which keycap is pressed first, pressing A+B or B+A should trigger ACTION_MODS_ONESHOT(MOD_LSFT)

But this works 50% of the time, also sometimes the LSFT gets stuck, only pressing the LSFT manually gets it unstuck

(I'm using the usb-usb converter, so I'm wondering whether the speed related problem might originate from that, I need to press A+B together for at least 200-300ms for the one-shot to trigger, momentarily tapping them together doesn't work, even though I make sure they are pressed at the same time)