Steps to replicate the issue (include links if applicable):

• Visit https://www.wikifunctions.org/wiki/Z558
• Click 'edit' (between 'read' and 'view history')
• Add the Bengali (Z1011) label 'প্রোগ্রামিং ভাষা' to the key (Z558K1) with English (Z1002) label 'programming language'
• Attempt to save the edit

What happens?:

The save fails with the error "User does not have permission to edit"

What should have happened instead?:

The save should have succeeded.

Software version (skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):

This has happened on other error types like Z503 (where I could add a Bengali object label in one edit, but could not go back and add a Bengali key label in a later edit), but does not happen on e.g. types (like Z99) or functions (like Z10670).