Item can be duplicated if you will hold it in OFF_HAND slot while triggerring /pa join command
Steps to reproduce:

1. get item in OFF_HAND
2. use /pa join to join some parkour
3. after teleporting item should stay in OFF_HAND slot (while all the other inventory will be temporarily removed)
4. drop the item on the ground
5. leave parkour
6. item in OFF_HAND will appear in OFF_HAND like the other inventory
7. repeat from step 2 to step 7

version: v7.2.2
please fix this