Bug: Date-picker Popup fails to open on Message Reminder (via chat bar)

Bug: Date-picker Popup fails to open on Message Reminder (via chat bar)

When I try set a reminder on a message I've received via chat bar (Cliq) in CRM the reminder date / time picker icon does not work. It should open a popup window with a date / time selector but it doesn't.

Image attached.

I've tested this in Safari 12.1.1 and Chrome 76.0.3 and neither work.