Is VS up to date?
A silly question, how are you starting your application to debug it? F5, CTRL+F5, Clicking the fully filled in play button, or the one that is just outlined? I find sometimes I have to go back to step 1 with even the simplest weirdness (I've be using VB since it became a thing in the early 90s)
Have you seen this
https://learn.microsoft.com/en-us/tr...ng-breakpoints
You could try to repair visual studio, via visual studio installer, click more and then repair.
You can reinstall visual studio, but then you do make sure to also use InstallCleanup afterwards (as outlined here
https://learn.microsoft.com/en-us/vi...o?view=vs-2022)