I've had this problem for perhaps 6 months (pretty sure it didn't happen in the distant past). The auto-complete panel fails to disappear after use or on pressing escape, often obscuring the target pane in which I'm trying to type in the process. The solution is to find an empty space and type something that will produce a new auto-complete suggestion then press escape.
Any chance of a fix?
It works here when I press Esc or the space bar, but sometimes it just doesn't happen.
I was able to reproduce this issue by holding the Backspace key while the Prompter was displayed. The quick fix has been pushed into the latest CTE Doughnut update 10.7.1. If you have already applied this update, please download and repeat the same update again. Thanks!