Active and public Homepage does not show in dropdown options

On a homepage in the dropdown options to select a different homepage, it does not show name of a homepage which is public and active.

All

There is a field 'selectable' on the form for that Homepage, which is not checked.

If selectable is not true then it does not allow the homepage to be made default homepage for system

1. Navigate to Homepage Admin >> Pages and open record for missing Homepage name from dropdown option.
2. Check the selectable field. Refer tot he screenshot attached above in cause section.