problem with sygic map and calculation route

I buy recently the sigic gps 16.1.2 with the map fra.ta.2015.12

and got some really strange things happen

the calculated routes are wrong ; sygic gives me routes that are much more longer in time and distance ; even the obvious route is direct and easy ... really strange calculation 4 minutes longer on a distance of 18 minutes . when i drag and drop this route on the direct shorter road the calculation answer is ok 14minutes .. ???

other time sygic calculates roads in grass that are only small and forbiden ? ( the option in sygic are only asphalt roads and quicker routes)

any suggestion .. it is really disappointing ..

should i try old maps ?? is it possible to use other maps than the one from sygic ??

why those enormous errors of calculation even on simple routes ??

thanks for you help