What-If Grades fails when trying to change a missing assignment

[clickthecreeper]

Describe the bug

When the grade on a missing assignment is changed, the entire page is highlighted, and once de-selected, the assignment cannon be interacted with.

Steps to reproduce

1. turn on what-if grades for a course
2. attempt to change the grade of an assigment which is marked as missing.

Expected behaviour

The assigment should be editable even if marked missing.

Screenshots

before: after: after de-selecting:

Platform

windows 10, google chrome (latest version)