Hi,
In Multiselect editor with open state prevented the component stops accepting mouse clicks as a way of moving cursor.
You can find repro here: https://stackblitz.com/edit/angular-u1j1p5-grc1nk?file=src%2Fapp%2Fapp.component.ts
Just copy/paste or type some text and try to change cursor position in word/phrase in order to fix something inside provided word.