When a User´s Username is an Email with capital letters, the login validation only works the first time

Description
When a User´s Username is an Email with capital letters, the login validation only works the first time, then if you try to log in it will give an error.

Pre-conditions
Have a User with an Email with capital letters as Username.
Example Username: user.example@IDERA.COM

How to reproduce

1. Create the User with the previous Username
2. Click to open TCD from Jira
3. Login with it and log out
4. Try to log in again

Actual result/Attachments
It retrieves the following error

Expected result
It should allow you to log in.