Filled-in cloze word wiped out by Ctrl-Space

Once I’ve filled in a cloze word and hit “Next”, the cloze word should remain in the field and should be read-only (whether printed in green or red). Instead, the field remains editable, and hitting a key combination like Ctrl-Space (repeat audio) empties it out. After this, it’s impossible to see the cloze word, or to select it in order to do a search on it (to pull up links to Tatoeba, Wiktionary, etc.). This is true in both light and dark mode. It happens in Chrome and Firefox on Windows.