Thank you for the descriptive post! I was looking through the community forum and our documentation and I found some resources that might be helpful to you.
Here is a forum post where another community member asks a very similar question:
@dzung gives a great response. Essentially, this functionality is by design - we want to prevent the points and billboards from obstructing the terrain when we zoom in. The response also provides a link to an active GitHub issue:
This issue goes over various workourounds that might be relevant to your use case.
Let me know if you have any other questions or concerns!