Please - if your previous setup failed - undo it - that means disable services and remove configurations.
If you are able to - you can also compare this guide to your current setup
→ [root tip] [How To] TigerVNC Quick Setup
I have done this so many times - I know it work as expected.
I suggest you stay away from assigning users to :1, :2 and :7
display :1 is used by greeter
display :2 is used by plasma (systemd default)
display :7 is usually used by desktop (following older tradition)
You can verify if the display is used by switching to the relevant TTY using CtrlAltF-num