Network manager menu is not stable; clicking on a VPN is dodgy

 * Cinnamon 4.6.7
 * Distribution:  Mint 20.0
 * Graphics: Intel i950
 * 32 or 64 bit:  64-bit
 * Attach ~/.xsession-errors, or /var/log/syslog

Issue
The Network Manager menu shows wifi AP SSIDs as they are discovered. The first time I open the menu, it may have two APs listed. My VPN connections appear at the bottom of the menu. When I try to click on my VPN, more APs may be discovered and the menu can grow. This frequently causes me to accidentally click on a different AP instead of my VPN. Of course, this kills my network and any active connections I already had opened, and it requires me to go through extra steps to get my WiFi reconnected and then, finally, to connect to the VPN that I wanted originally.

Steps to reproduce

1. Click network menu
2. Point mouse at bottom of menu near "VPN"
3. Notice how the option moves when more APs are discovered

Expected behaviour
Buttons and menus are stable and don't dodge my mouse clicks

Start by reproducing the issue with the network menu: open it, move toward the VPN entry, and observe whether newly discovered access points shift the menu. The payload names no source file or test, so locate the network-manager menu implementation before making changes. Done means menu entries remain stable while access points are discovered, without disrupting VPN selection.