Wrong transferred. Carry best with pom. cloning / migration plugins that fix serialized arrays. Eg Duplicator .
Most of the methods described on the Internet mean that siteurl and home values are replaced in the wp_options table. This information is outdated. They do not take into account the paths to files and the use of addresses in serialized arrays. what is used in many modern theme, plug-ins and even in the settings of the VI. This is fraught with various problems - from the loss of widgets and styles to the non-working functionality of themes and plugins. Well, there are other, less obvious errors and problems of "incomprehensible" origin.
Correct fixes after the transfer can be done with this script . But you need to act carefully and multipass - from large entries to smaller ones, constantly checking in the demo mode what and where is found. Do not forget about the presence of screened special characters in the database.