LifelessJelly

Try contacting microsoft helpdesk, they will give you a code directly, worked for me

Update: checked an old realm world that had dungeons with chests, by creating a world with the same world. It did have chests. My bad. This bug report can be marked off as resolved.

I've seen Channeling on sale before, forgot about the other enchantments

Try switching the minecraft file path from application to external. If this doesn't work, check your minecraftworld files. They may either have been deleted, your worlds have a missing element in your db file (db files include .log, .ldb, CURRENT and MANIFEST) or missing .level file.
(If anyone knows how to recover these, reply to this comment) If the resource_pack or behaviour_pack folder is gone, try creating a new one