The '+' on the Task Grid does not allow to create task in Modern UX Grid.
Expected Result: Task to be created
Actual Result: No response from page
Note: Issue can be replicated for some default boolean fields as well; example: "is_late", is_task".
This is caused by Clarity Defect DE63454.
The defect is fixed in 16.0.1
Workaround: Move position of "Open for time entry" or boolean field to the second column.