Hi,
in the meanwhile, I discovered that the problem is caused by a plugin: Search&Filter Pro (by Design&Code).
I already contacted the plugin support.
Anyway, could you give any advice about it?
If the problem doesn’t solve (and I’ll have a serious problem as I must publish the site in a few days!), do you know a search&filter plugin compatible with Enfold?
Many thanks,
Alberto

Thank you Yigit, I’ll update.
Albe