@leocg I did a backup of bookmarks, then uninstalled it, asked to erase my previous user data, cleaned out the Opera directory, reinstalled it in another folder and now it's working. PayPal actually opens another page to fill in password, but I didn't get anywhere in the old version and now I do. Thanks for your time & help!
Go to Chrome Settings > Privacy and Security > Site Settings > Autofill and payments and turn off Save and Fill addresses. Also, check Permissions > Location and block it. Restart the browser.
I have the same problem on Windows (I think OS doesn't matter). Chrome Extension "Microsoft Single Sign On" doesn't work properly in this case (in Chrome it works fine). We need special extension for Opera.