Issue Summary

Unable to change authentication method of incoming mail server to basic authentication from OAuth 2.0. When editing the mail server configuration you are able to select "Basic Authentication" > Input the app password > and test connection which results in "The connection was successful.". However, after selecting "Save and authorize" and then reaccessing the mail server configuration the authentication method reverts back to the OAuth authentication method.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Access incoming mail server configuration by navigating to Jira Administration > System > MAIL > Incoming Mail > Select "edit" for the mail server that you will be changing the authentication method for.
2. Update the Athentication method from "OAuth" to "Password (basic authentication)" > update the password > Test Connection > Save and authorize.
3. Re-access the mail server configuration and you will find the "Authentication method" reverts back to "OAuth"

Expected Results

The authentication method would update to "Password (basic authentication)" after saving the changes

Actual Results

The authentication reverts back to "OAuth" after saving the changes

Workaround

In order to update the authentication method for the mail server in question, you will want to delete the existing mail server and create a new mail server setting the Authentication method to "Password (basic authentication)"