unselectable edge showing only when smotted Iseed to have unselecteable edged that I can see only when in "Z" mode or Object mode but not in edited mode:

Edited mode - no edges:

Edited mode with "Z" - Unselectable edges

Object mode, edges take shape


How can I solve this ?
You have probably hidden this part in the edit mode, press AltH in edit mode to unhide the part of the mesh.