I know this is a bit old now, but I believe your issue may be any material that is transparent. I ran into this same issue in the past. There doesn’t seem to be anything you can do for your glass (that I’m aware of), but for the flower, if you’re just using a material blend mode of translucent for masking the leaves etc, try changing the blend mode to masked instead. You might have to bump up the resolution of your mask to keep edges clean, but it will react properly to the focal blur after that.
Unfortunately, I think this is a property of the current render approach: Unreal Engine Issues and Bug Tracker (UE-61596)