Mandatory to set region for Login API?

Pre condition, Condition to reproduce

Try to create Line Channel - Login API

Issue/ Error Message details

"Region" setting is mandatory

Accompanying respective source code

Resolution Tried

Reference information (Version / Platform/ environment)

When I check my previously created channels in the same provider, the value for "region" is "-", and it seems to work for Line accounts from various regions. But I'm trying to create a new channel for Line login purposes, and it is mandatory to select just one region, with very limited options. Has the policy on creating Line Login channel changed? If so, is there no possible way to provide Line Login for customers in regions outside the suggested options? If that is the case, is there a possibility my previous channels will stop working for customers in other regions?