Hi,
to migrate a site form a server A to a server B I tried many times before success.
Even in this forum, I didn’t find a clear explanation of what to do exactly.
This is the way I did proceed after many tries : 
- On server A, in the neos directory : ./flow site:export --package-key “Mycompany.Package”
this will create a site.xml file in the package Mycompany.Package folder (located in the Sites folder)
-
On server B, install a new neos instance with Neos.demo site example
-
On server B, in the neos directory : ./flow site:prune
This will clear all sites installed
-
With ftp or over ssh, copy the package Mycompany.PAckage folder form server A to server B, at the same place
-
On server B, in the neos folder : ./flow flow:package:rescan
This will allow neos to recognize the new package pasted on the file system
- On, server B, in the neos folder : ./flow site:import --package-key “Mycompany.Package”
On server B, your site should work now.
After this steps, you can try ./flow resource:publish if some of your medias are not visible