I'm running LR Mobile v2.7.3 on my iPad Pro, iOS 10.3.1.
Sometime recently, perhaps with the latest iOS update, the widget stopped working. I don't use it often on my iPad, so not sure when it stopped working. Here's what I see. For comparison, my iPhone 7+, iOS 10.3.1 and the same version of LR Mobile, the widget works just fine. Here's my iPad screen shot: