I have MY20 with Columbus (not sure if its MIB3 or not) but it works perfectly using this process
1. Use MySkoda app to create route. Optionally name it. Send to car
2. Once in car, start Navigation
3. Select "My Dests" from the lower menu bar
4. Car immediately informs me that "1 online destination(s) imported"
5. Select "Display online"
6. Check its the destination you want
7. Go!
If you want to recall an imported destination later, you can
1. Start Navigation
2. Select "My Dests" from the lower menu bar
3. Select "Destinations"
4. Choose the destination required (they are all saved)
If the destination you want is not displayed, make sure the display is set to "Online dests" in the menu top right (options are Dest. Memory/Favourites/Contacts/Online dests)
One "funny" that I have found...if you are actually in the car with ignition on, the MySkoda app can find a location but seems unable to calculate a route, so there's nothing to send. In the house, it works perfectly every time