Can't edit node properties in crx/de after asset is checked in

In the terminology I'm familiar with, "to check something out" is to reserve it. "To check something in" is to commit your changes and free it for future use.

I have some server-side code that performs some operations and creates a new node after a file is uploaded. After I check this new node out and check it back in again, I'm getting an error when attempting to tweak it in crx/de:

Could not save changes. Received 409 (Conflict) for saving changes in workspace crx.default. Cannot set property. Node [name] is checked in.

But, I thought if it's "checked in" then that means that it's free?  Or if I have to check it out again before it can be used, how can you "check out" things through crx/de?

Also, can I avoid this altogether by making my node of a certain type, so that it doesn't need to go through any of this? I don't have problems editing other nodes, through crx/de