Getting first person gun and arm animations working together (two separate rigs)

I have a gun model and an arms model in Blender, and I have multiple animations set up on them (reload, attack, walk, etc.) I've pushed down the animations to NLA tracks in Blender, and I exported the gun and arms as two separate .glb files. Now, I want to sync up the animations on them, so my arms will move correctly with my gun. Unfortunately, I can't get everything to match up. This is what happens when I try to run the correct animation on my gun and arms. I tried baking my animations, but I'm having trouble with that too.

The weird thing is, I had the reload animation perfectly synced up before, but the shooting animation was messed up. I exported it from Blender again, and now both are messed up.

Here are my project and .blend file: https://drive.google.com/drive/folders/1FBFpkUg1TlnolAFcDC23Zbyk0Bs9nZPC?usp=sharing

Here's the code I'm using to play the animations:

func _input(event: InputEvent) -> void:
    if Input.is_action_just_pressed("reload"):
        $m1911/AnimationPlayer.play("m1911_reload")
        $m1911/arms/AnimationPlayer.play("arms_reload")
    if Input.is_action_just_pressed("attack"):
        $m1911/AnimationPlayer.play("m1911_attack")
        $m1911/arms/AnimationPlayer.play("arms_attack")