On most recent version due to it being a realm.
While the realm owner has no issue with seeing the addons as they have the packs downloaded locally, other players have reported that the various marketplace addons seem to not be visible with it being a random one/set of addons each time. At first it was assumed the texture pack might be the cause. But even after removing the texture pack the issue still persists. Even when loading in and getting the instruction/start up books it appears as a invisible item to them but other players with the addons working properly sees the item as it should be.
The players that join have been using the Xbox series X, a Nintendo switch and, a Ps4. With each system receiving the same issue. While the only workaround that only slightly works being to clear marketplace cache and delete the temporary download of the addon after leaving the realm. Then rejoining and hoping that the addon does work. Though that usually does not help.