i originally thought this was an issue with the vscode deb but it seems to be an issue with mintsources, see microsoft/vscode#264431 (comment)
Steps to Reproduce
- install the
.deb from https://code.visualstudio.com/insiders/
- enable the checkbox to add the microsoft apt repo during installation (i did this with linux mint's installer, not sure what that looks like in the CLI)
- open "software sources" and check "additional repositories" and ensure the microsoft repo is enabled (might need to enable it initially, i don't remember):

- wait for an update to vscode-insiders, then install it with linux mint's update manager
- navigate back to software sources and see that the microsoft repo has disabled itself:

system info
- Linux Mint 22.2 Cinnamon
- mintsources 2.3.4