If your issue still persists - would you mind to run simple compatibility check.
Could you please try to resolve your issue by deactivating all third-party plugins as well as the default theme to check for any possible conflicts with any of the plugins or themes?
If the above step does not help:
Can you please share access details so I can check whats going wrong with your setup.
*** Please make a FULL BACKUP of your database and website.***
I would also eventually need to request temporary access (WP-Admin and FTP) to your site. Preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed.
I have set the next reply to private which means only you and I have access to it.