When you try to access your phone via Phone Link on the PC and the lock screen on your phone has activated, you get the popup pasted below. Means you have to go find your phone and manually remove the lock screen before you can access the phone via Phone Link on your PC. Kind of, actually, totally defeats the purpose of Phone Link to access your phone.
Hi JuliusRK, I am Paulo and I'd like to help.
I believe there's no option in the desktop app that causes this behavior. Can you verify if the problem happens instantly when you lock the phone? What message or error do you get in the app when this problem occurs?