I have the same issue with my FR 955 solar during indoor and outdoor runs. The a dotted-line appears then disappears after I upgraded to the new software version. The location of the lines changes on the screen.
To answer my questions :
- May we, if necessary, have permission to email you? YES
- May we, if necessary, have permission to view/access your Garmin Connect account? YES
- In what country do you live? IRAN