Issue logging in using JWT-AUTH / REST API with Username

Hi, hope someone can help. Using the most recent version of LL.

We have an App that logs into WP via the REST API and the JWT-AUTH using the user’s username (not email address).

This stopped working some time back. Testing with Postman using the user’s email address works. But attempting to login with the user name, the login fails (error 403).

The IP address is listed in the login_fails table as “::1”.

When disabling LL, login via user name works. Obviously I don’t want to disable LL in our production environment.

I have tried whitelisting “::1” but that hasn’t worked, and I didn’t really expect it to.

Does anyone have any suggestions on how this might be fixed? I would really appreciate some assistance.