I have the LG K20, sure it's a bit of an older phone, but still runs Android 7.0 Nougat. I did have to remove the software token via the page manually first as well, and then install the new APP. However the first time, same problem as you guys, it didn't load or so I thought. I removed it and installed it again, same thing. I then opened the APP and went on with my life, after 10 minutes it did load the "welcome to the security app" screen and let me put all the information in. It seems the first time it gets installed, it needs a specific amount of loading time, not sure why but try that. Open your APP leave it alone for 10 minutes, check up on it, might have to close it one more time and run it after. However after that's done, the APP works without any issues and loads within seconds, just that initial after install opening seem to take it's sweet time lol.