The problem of Apps not showing proper icons, when moved to SD card can be solved as follows:
I have a Note 8 with a Samsung 256 GB SD Card.
When I move eligible apps to the SD card, the icons show up as greyed out, with the annotation "SD".
To get the proper icon display again proceed as follows:
1. Go to Settings/Device maintenance/Storage
2. Click on the "3 dots" at the upper right of the screen
3. Select: Storage settings
4. Select "SD card", then click on "UNMOUNT"
5. Wait a few minutes until the SD card is unmounted. A message will show it to be finished.
6. When the SD card is unmounted: Select and click on: "Mount SD card"
7. When the SD card is mounted again, all the apps show up again in the app drawer, with their proper icons.
8. Copy missing icons on the Home screen from the corresponding app icons in the app drawer.
9. If it does not work properly, repeat steps: 1 through 8.
Good luck,
Peter