Inconsistent behavior of Headings

I’m having a little trouble understanding why my H1 nodes behave differently from the H* nodes.

I am using the “schema-basic” schema as a base. I am not changing anything about the heading nodes.

After I add an H1 heading at the beginning of a document, I can no longer select or cursor into the H1 heading. Other headings behave as expected.

Has anybody else seen this? Can you help me troubleshoot this?

Since this doesn’t appear to be happening on, for example, the demos on https://prosemirror.net, a first step would be to figure out what’s different in your setup that’s causing this.

can you brief me on why I couldn’t edit a header node?