Underscore prevents search in space directory

Summary

Space directory search filters fails with underscore

Environment
Confluence version : 5.10.x and I was able to reproduce on 6.1.3.
No plugins no proxy used no SSL

Browser versions:
• All 3 browsers are affected

Steps to Reproduce
1. Log in to confluence
2. Navigate to space directories when searching with space name that contains _ nothing is found
3. Tested with dash and results were showing
Screen shots showing:
1.full list of spaces
2. result of underscore- not showing output
3. result with dash filter- showing output
Expected Results
To have results similar to dash