Avatar Mask Excluding Weapon on Rig

I’m trying to animate my character to shoot a revolver while still keeping their Idle animation on all but their left hand ( the one they shoot with ). However I’ve ran into an issue where my weapon is being excluded from the animation.

Here is an imgur link with video of how it should look and how it does look (because I cannot post mp4 here)
6548083--740863--upload_2020-11-21_20-13-14.png
These are all the bones I have checked in my Avatar mask ^

Any help would be appreciated thank you!

I’ve never used Transform based masks like that so I’m not sure if there’s a proper way to do it, but you could always use Events to show/hide and reparent the gun.

The Multi-Parent Constraint in the Animation Rigging package might also be helpful.

Also, if you record gifs you can post them directly here. Screen to Gif is very easy to use.

I already have that setup with UMotion Pro, that’s why it works normally in scene, so it must be something to do with the behavior of Animation Masks, I tried to do it without actually importing skeleton but that just makes my animation really messed up (gun was like 2m in the air)