Calendar Gear Fit2

This is a really great app, but am having problems keeping it on the watch, it works for about 10 minutes and then goes to a permanent blank screen. Seems to be an issue with the newer Android systems like 8.0.0. It's as if it is going into some sort of energy saving mode, but will not wake up. Update, after uninstalling and installing it countless times and finding in systems where to check 'ok' to it being loaded from an outside source, I never could get it to stop going to a gray screen. It is a really beautiful app but will not stay installed if you are are using Android 8.0.0

Ok, it uploaded to my phone, thats it, I have a new calender app on my phone, how do i get it on my watch? Delete and start over? I just deleted and reinstalled, hit OK to install in watch, no dice....not sure it is possible with android 8 as the permissions tab for sideloading apk is gone, in response I have uninstalled and reinstalled, permissions is different in 8, the app loads to watch, but eventually i just get a black screen when i tap the icon on the watch.... Ends up a complete fail