My husband and I just got new phones yesterday and we are each having the same problem: the security key app, that we had been using on our old phones, does not work on our new phones.

Old phones: LG G3, with Android 6.0.
New phones: LG Stylo 3 Plus, with Android 7.0.

We followed the steps for removing the registration for the app from our old phones, as provided at this page (which is also provided in the pages in account admin about registering and using the software token). But when we each open the app on our phones, we get nothing-- just the screen for the app with the little "loading" keyhole icon, and nothing else happens.

I was hoping someone here might have had a similar issue that they managed to resolve.