How to associate computer_id with endpointId

There's an existing post that went unanswered about this same topic:

Endpoints contain an id, which some events contain as endpointId. However, some events only contain a computer_id, no endpointId. The ids are not the same.

Is there some way to link a computer_id to an endpointId? Why do some events not include endpointId?

I have already looked through the docs and cannot find any explanation around this, so please do not link to them unless it's to the exact answer. How to connect the ids, or why some events can't provide the endpointId is something that should be in the docs. It's not something one should have to contact support for.