Menus are not appear on all new created sub-site

Hello

For some reason, I cannot create menu in all new sub-sites.

I clone a sub-site to be new one, then create a menu, then noted this is not appear..
everything I create on Appearance ? Menus just gone after clicked "Save Menu", I tried to Google and added below codes to my PHP editor on WHM on server end.
suhosin.post.max_vars = 5000
suhosin.request.max_vars = 5000

and also expanded "max_input_vars" to 5000

but still no help.

I created another wordpress on same server, then copy the new created sub-site to that new created wordpress by Snapshot, then I can see all items in Menus, so I think those items just cannot appear in my wordpress?
- it seems not related to PHP settings (those 2 wordpress are sharing same PHP ver.),
- it seems not related to theme, since I copied theme also by Snapshot..so those wordpress are using same theme and setting.
- it seems not related to plugins, I tried to 1 by 1 Network deactivate plugins to test with no luck...

Can you please help to suggest me next step to trace this issue?

Please...