There's some funky shit going on:
- Moving weapons around causes them to lose attachments
- Stacking weapons with AllowStackingItemsWithDurability turned on or off in the hotbar will cause the weapon with the attachment to lose the attachment
I've uploaded a video to YouTube to demonstrate: https://www.youtube.com/watch?v=ZTH3fFcMjwo
I've included the settings for our plugin in the attached zipfile...
ISSUE.zip