One of the folders within the datapack folder was named "overworld", after uploaded to Realms it got replaced by "over<My_Realm_Name (world 1)>" causing the datapack to not work.
Summarize: Folders that has "world" in the name gets changed into <My_Realm_Name (world_number)>
You should only make it changing the main world folder's name, not all folders. Thanks!
Linked issues
duplicates 1
Comments 3
Duplicates REALMS-5452
Yeah I'm gonna resolve forward this to REALMS-5452, since there is more traffic on that ticket.
I've removed some redundant information. Hope you will be fine with this.