It seems that the problem is only relevant for realms. I downloaded the world and played it locally. And no problems with armor display update!
I only used packs from the official marketplace. DINOSAURS / Camo Hide and Seek / Advanced Creepers / TNT Plus
The update error only occurs whe using realms. Hosting the world by myself, the error doesnt occur and chaning armor is visible instantly by other players.
Moving out of drawing distance and then coming back to another player provoces an update of the displayed armor.
Changing armor again is not visible for others. Moving out of drawing distance again updates the status again.
When somebody changes their armour (like taking it off or putting it on) it does not show that to other players, which can cause an unfair visual advantage.
Hide and Seek Mods are impossible to play. Apears on PC 1.18.31 as on Switch 1.18.33 playing together on Realms.
I experience the same issue with the package "Escape Room: Illager's Mansion"
Bedrock on PC 1.19.0 and Nintendo Switch 1.19.1 wont work. Updating the package is not possible. The window simply closes. But creating the world until updating is not possible. So no way to play the recently bought packages.