Describe the bug, provide any errors
By clicking on an item in a gui, the item is duplicated

How can we reproduce it?
Steps to reproduce the behavior:

1. Login on 1.8.9
2. Open a GUI
3. Click on an item (one or more times)

Expected behaviour
The item must not be doubled carried around

Screenshots

ViaVersion Dump:
It is not necessary. You have known the bug for several years, it is time to try to fix it

Additional server info
Velocity

Checklist (mark with [X] to check)

• [] I have included a ViaVersion dump
• If applicable, I have included a paste (not a screenshot) of the error
• I have tried a build from https://ci.viaversion.com/ and the issue still persists
• I have looked at https://www.spigotmc.org/resources/viarewind-legacy-support.52924/ and it does not offer a fix for my problem

This issue has nothing to do with ViaRewind but with ViaBackwards.