Hi, thanks for posting.
The 'Run all tests automatically' engine mode is fairly indiscriminate. It will run every test in a project that passes through the build system. Because there's no reliable way to know which files contribute to the build, any changed file in a project will trigger a build.
The best option in your case may be to try using the 'Run impacted tests automatically' engine mode instead. This actually performs an IL-level comparison to detect which tests are are likely to be impacted by a given change, and is more selective in what will be automatically executed.
Another option would be to mark the tests using a custom category that you can adjust the engine mode to specifically exclude from automatic execution. Or mark the tests as Explicit so they can only be run manually.