As I said, device. In principle, when the gps signal oscillates it is solely a hardware problem.
It is possible that the quality of their chip is not at an adequate level for whole series. Since it is intended for Navitel, it is also possible that the software is not as sensitive on signal changes. Or, the Navitel have some extra software fix for that.
Israel and Gift are basically same apps. Try with some other version - PAL, for example. Or start a row - then Avic, Basar, then T4A...