I have a pretty weird issue with the lockscreen.
When i lock my screen by any way ("lock" button in start menu, Win+L or even sleep mode), the lockscreen works, but when i type my password to unlock, my session just crashes and logs me out and i get sent back on the login screen.
To test, i started a music file. When i pressed Win+L, the screen locked and turned off, and the music was still playing, perfectly normal, i then move my mouse, the screen turns back on, still normal, but when i type my password and press enter the music cuts and well i get fully logged out, as i said earlier.
I do not believe power saving features on your OS are functioning properly. (A common issue on Linux) I would recommend going into your power settings, and turning off everything that has to do with power saving, like sleep for example.
On OS 17 & 18, you should have a power mode setting as well, put that on performance, if balanced is acting weird. I'm on OS 16, so this is all I get, other then my Nvidia performance settings. I have to use Dconf editor to adjust more settings, cause Linux keeps most of these kind of settings locked down.
If it says Wayland instead, this is what you are going to do. Log out of your desktop session. Then click on your name at the login screen. A gear suddenly appears. Click on that, then select Zorin OS, not Wayland.
If you are still having issues, you might need assistance from another mod, cause this is pretty much all I know on that. I just hope that I was able to help you.
icon in your taskbar, then click on settings. 
