I had this problem too on my iPad. iOS 14.7.1, Minecraft 1.17.11.
After reading this thread, I did the following to get it working for me:
Disabled Local Network Access from the permissions menu (it was already enabled)
Loaded the game. It still didn't work.
Went back to permissions and re-enabled Local Network Access
Loaded the game. This time the Marketplace works as expected
So it clearly has something to do with Local Network Access, but unlike others in this thread I needed to toggle it off and on again to get things to work.
Having the same issue on Xbox One. The treasure it was pointing to was over 2000 blocks away. I found the treasure and destroyed the chest but the issue still keeps occurring. This also occurred following the most recent update.
It is critically important that Microsoft/Mojang understand that this common text issue (text not working in many game elements/modes, apparently mostly in Australian realms) is replicated, tracked and updated across several different bug tracking numbers by different users who all confirm that it has been ongoing for a very long period of time. The frustration levels can be easily felt and to us users as outsiders, it does appear to be largely ignored and dismissed. The other active, open bug reports includes REALMS-9214, REALMS-9223, REALMS-9150 and the biggie REALMS-9191. Perhaps all affected users should join, follow and update all of these active reports to ensure our voices are heard.