I have found another way for Sygic to work on devices with Lollipop on external SD Card, in my case HTC One M9.
Copy your Sygic folder to the external SD Card, install everything what you need and put apk on external SD Card but not in a folder.
Now install your apk and that's it.
In case if you have new version of Sygic just install over the old version, run and wait to download some files from Play Store and that's it!
Same thing with SygicTruck, always install apk from external SD Card but must to know is that SygicTruck folder you can find on your external SD Card in Android / data/ com.sygic.truck / files / SygicTruck