Hello, Plusout,
1/ We have not made any changes to your staging site, this effect is possible when switching between the child and parent themes and vice versa. You just need to go to the customizer and save the changes.
2/ Steps 5 and 6 should be done. We need to know if the result is dependent on the options, which is why we are taking this step. If it does not work and then works again after reverting the options, we will be sure that the problem is with one of the options.
3/ After that, search for the option that is causing the problem can be done.
Kind Regards,
8theme team