Can't delete after manually using "showMenuForCollection"

[AmrN]

How can we reproduce this bug?

1. Open example page
2. Click on "@mention" to open menu.
3. Choose any item.
4. Press backspace multiple times.

What did you expect to happen? inserted item should be deleted.

What happened instead? Nothing, cursor is stuck.

Tested master with Chrome and Firefox.

[hosnar]

Did you manage to solve this?