Can you preload or onready a joystick button?

I'm having issues getting my joystick buttons to work consistently. Everything is set up correctly, however launching the game it seems to be hit or miss. Sometimes the buttons will work just fine, other times it's like they never got detected from the start.

This made me curious if there was any way to set up or establish the buttons at the beginning the way you would with an onready var. I've looked at the doc pages but am having trouble making heads or tails of it, especially using 3.5.1 instead of 4.x

Thanks for any insight you can provide