Since the upgrade, the visual result of reducing the opacity on a layer has changed ... for the worse, in my opinion.

As you moved the slider, it used to show on the image how much you were reducing it. Now there is no change, even when you tap away the layer settings box. It waits for you to tap on the screen, which took me a while to work out. I was even making another layer, then merging it down, which worked, to get the end result.

How can you tell how much you are reducing it? It needs numerous fiddles to get it right.