Intermittent altitude read from home altitude to above the sea altitude

hi guys, i have this odd situations very often, the altitude reading sometimes replaced with altitude above the sea level, its very anoying sometimes especially when we make a long range flight i can’t determine the altitude corectly

*altitude show at OSD same as altitude showed on mavlink

please skip to 6:14 to watch altitude change from home altitude into sea level altitude

so the questions are
1st. what cause that make it happen?
2nd. if we on auto mode (cruise / auto / fbwb) when that happen was apm decide to dive to correct the altitude? (that’s worried me)

thank you in advance

no one? i’m still don’t have any idea what cause make this behaves :frowning_face: