I am seeing this same behavior. It has been going on for a few months now. I thought it would get resolved in an update, but it is still happening. I opened a support case this weekend. We'll see what they have to say.
Very frustrating. It crashes about half the time I relaunch it. Instead of prompting for my Touch ID, it just displays the white screen with lock for a few seconds then crashes.
I am on an iPhone7 with iOS 11.1.2, though this has been happening since around the time i upgraded to 11.0