Spell Checker: multiple selection then choosing "Ignore" causes system to freeze

[paperback]

Linux 20.1 / Cinnamon 3.86 / 2.40GHz × 2 processor / 3.7 Gb memory / Calibre 5.38

TO REPRODUCE

You may be able to reproduce the issue by using an ebook with a large number, perhaps a few hundred items, in the spell-checker list.

1. Open the spell checker.
2. Select a large number of items, several hundred if possible (in my case most of them were in ancient Greek script, so perhaps this may be the trigger?).
3. Right click on the selection and choose "Ignore all selected words".

RESULT: The system becomes unresponsive. May require a forced shut down.