Filter to find mentions is not working with currentUser()

Summary

When using filter, for example, (summary ~ currentUser() OR description ~ currentUser() OR comment ~ currentUser()), it does not return any results.
If we change the currentUser() for the username, it works.

Steps to Reproduce

1. Have an issue where your username is included on a comment, description or summary.
2. Search for summary ~ currentUser() OR description ~ currentUser() OR comment ~ currentUser()

Expected Results

It returns the results for the current user logged on the instance.

Actual Results

It returns nothing.

Workaround

Change the currentUser() for the username.