@vasco2020 I have just tested this for you on another computer.
Note to Opera people: I am an IT consultant and a programmer. Your installer is an absolute disgrace. I know this software is free, but that is no excuse for this nonsense:
I uninstalled Opera.
I downloaded the current version and ran the installer.
During install I clicked the tiny little almost invisible link for "Options"
Changed the "install for" to All users of this computer
Browse to the c:\program files folder for the "install path" - This Is Wrong . The idiot program does not create the "Opera Browser" folder for you within Program Files! I am utterly shocked by this. So you must first browse to your Program Files folder and manually create a folder called "Opera Browser" or something that makes it obvious what it is. Then browse to that folder in the installer and finish the install.
I am utterly gobsmacked at the unprofessionalism of this and it worries me greatly now, about other aspects of the software such as security.
Anyway, once the install is complete and I run the browser again, all my favourites etc. are still there so it must have imported them.