Interpreting flat-line graph results on Muse?

Hi there - I’ve tried muse a few times and have consistently been seeing flat-line 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 online so wanted to check here - would appreciate any help troubleshooting or translating?

Ive never seen flat lines like that before, mine are many many peaks and troughs ( but with similar overall shape to yours). Strange