Hello!
Any new action on this issue by chance Peter? It is still happening to me, but wanted to add another caveat that I don't know if it will help or not. I received the Samsung Gear VR as a gift and use it with the 6 Edge. After I am done using it and exit out of the Oculus/Gear apps and go back to the home screen, the icon is gone as well. I'm not sure what the VR headset does to the phone, as in what kind of state it puts it in, but whatever it is causes the icon to disappear as well just like a reboot does.
For kicks, I added a 1x1 shortcut for the calendar to one of the screens and that icon disappears as well. And it appears to only occur with Touchdown icons. The 1x1 icons. I use the Calendar and Tasks 3x2 widgets and those never disappear. Just the 1x1 shortcut icons do.
Thanks