The bug
When you fully charge a crossbow and still hold right-click, instead of loading the arrow, it just jumps back to the original position of the crossbow until you let go of your mouse. Then, the crossbow will jump back to the center of the screen, looking rather odd and seems unintentional. The Bedrock version of the game does not have this issue.
Linked issues
is duplicated by 1
relates to 2
Attachments
Comments
Can confirm in 21w06a.
Seems like a duplicate of MC-148813.

Can confirm in 1.17.1. If anything, MC-148813 should be resolved as a duplicate because this issue has an assigned Mojang Priority, and is updated more frequently.

Confirmed with 21w38a
An example of this is a pillager/piglin loading a crossbow and automatically loads it.