
While you’re doing some type of animation (for example, reloading) and then jump, your hand position returns to the begining one, making your clips/magazine magically float into the gun (Or when bolting the gun). When you land, your hand then returns back to playing the animation. Easily repeatable
Step 1. Initiate any sort of animation (Reload, bolt weapon, etc.)
Step 2. while in mid animation, jump
Step 3. Repeat the process and see the magical clips.
Done

Yes this is a known issue, also when tabbing out during a reload animation this happens. No Animation should cancel the other. I will ticket this.
Again great reporting.