That looks to be regular behaviour for GCP. If no other point has been entered after DL, then ENTER starts a line from 0,0. I have not noticed, before trying now, as I always start a line with a left mouse click with or without snap.
Placing the line gets you out of this catch but ESC makes it persist. Even a first command like MO or MR takes GCP out from this bind. Interestingly it does not occur in an empty "UNTITLED" screen, the line there starts at the location of the cursor as expected.
This does not happen in GC.