Entity procedure not working correctly

I need some help with an enchantment I'm currently working on. The two procedures for the custom enchantment are as follows:

1st procedure; When a bow or crossbow is in your main-hand, and has said enchantment on it, it will set a custom global variable to 'true', otherwise, as 'false'.

2nd procedure; if the entity shot from the enchanted bow/crossbow is an arrow, the global variable set to true, and the arrow is on ground, the arrow explodes.

However, when I try and use this enchantment, it doesn't work at all. Here are some screenshots of the procedures: https://imgur.com/a/LQ0BOOv

I don't really know what went wrong, so I'd really appreciate some help ^-^