1. A concise explanation of the problem you're experiencing.
Not able to select entities while holding down shift or ctrl keys.
2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.
3. Context. Why do you need to do this? We might know a better way to accomplish your goal.
I have logic to be able to select multiple entities while holding down ctrl and shift, but Cesium does not allow one to select an entity while holding down one of these keys. How can I override this?
4. The Cesium version you're using, your operating system and browser.
Cesium 1.7.1, Rel7, Firefox