DST cosmetic inventory validation bug after admin commands and reinstall

Hello,
I am experiencing a serious cosmetic/inventory issue in Don't Starve Together.
The problem originally started after using admin console commands on my hosted server while trying to change another player's character.
At first:

• only my brother could not equip or change cosmetics on my servers,
• but his cosmetics worked normally on other servers.
• Now, after reinstalling the game, the issue has become worse:
• my own character also cannot equip or change cosmetics anymore.

Current symptoms:

• cosmetics exist in inventory,
• characters load normally,
• but cosmetics do not apply/change in-game,
• this happens on my hosted servers,
• multiple new worlds/clusters were tested,
• reinstalling the game did not fix the issue.