Reproduce:

• In Internet Explorer 11:
• Goto the Alerting section
• Open the create new Alert modal
• Click on the unit selection field next to the "Check Report every" input field

Expected:

• Selection field opens and stays open

Observed:

• Selection field opens and closes again
• Number Input field has focus

Hint:

• This also applies to the Remainder Emails unit dropdown
• Workaround: Keep the mouse pressed and move it to another open after the select opens before releasing the mouse button