Joining a realm you have been invited to, from the "joinable friends" tab, allows you to see world information such as: Game rules, world seed, resource packs, world name, default game mode, etc. You can also see player privileges, for all players currently in the game from the pause menu.

You can see ALL of this information, no matter what status you have as a player. Realm owner, OP, standard member, or visitor. Typically when you join a realm all of this information is hidden, even to the realm owner.

Having the game information hidden, is necessary for the life of a lot of realms that want to keep the seed private in order to avoid issues on that front. There is nothing you can do to combat this bug, absolutely nothing.

What i think is happening here, is that when you join from the joinable friends tab, bedrock thinks you are simply joining someones multiplayer world, and not an actual realm. The big thing to suggest this, is when you join from the joinable tab, you get the standard village panorama in the back round, and not the nether portal that is shown when you join realms.

All other behavior(being able to see player privileges etc) is the same as a multiplayer world too.

Video showing this bug in action: https://youtu.be/cASU8AMBSI8