It was vest and uniform. Backpack and headgear was not effected.

Not sure if this helps but when I ran a Altis Life server we had this issue for multiple years and we called it the "nexus bug" because the bug was introduced with/or close to the nexus update. A players gear would become invisible for all other players except for themselves, and if I recall correctly this issue occurred when a player switched seats in a vehicle (I don't remember if there has to be other players in the vehicle or not, and the issue didn't always happen so there has to be some other contributing factor). We ended up adding a button that "refreshed" the players gear as a temporary fix while waiting for an official fix. "player setUnitLoadout (getUnitLoadout player);".