I'm not familar with remote desktops but perhaps these links can help you. In ubuntu it is not exactly the same as in Zorin.
If you have auto-login enabled this can cause the problem that the password is reset after reboot.
So I'd recommend to go to settings>user and disable autologin and change it to a login with a user password. Perhaps this solves also your other problem.
Take a look at post no. 20 of zenzen
Also make sure that the slider at the top at tab "Sharing" is turned on. Sometimes when using light mode or dark mode it is nearly invisible on the screen.