Interpreting flat-line brain wave results with Muse?

Hi there - any Muse users here? I’ve tried Muse a few times and have consistently been seeing flat-line calm / neutral results for part or most of the session (example attached)

Have been trying to figure out if this is an error or how to translate these results, but haven’t had luck so far so wanted to check here - Thanks in advance for any help with troubleshooting or interpreting?