Maybe I fixed my problem with gps.
I tried a lot of settings and I don't know exactly what works well.
In energy saver choose performance mode
Reset to default startup manager (reboot)
Open startup manager and activate the apps "maps" and "position"
Open play store and instal the app "gpsfix" (no root is required)
Go to display settings and set timeout to 30 minutes
Open gpsfix and let it fix the position.
Open the app U need to use with gps.
After 3 or 4 times I used gpsfix my gps begin works well alone.
Now I have only changed the screen timeout to 30 sec. And I haven't changed any other settings (I'm afraid to do it)
The app gpsfix is still installed on my phone....
That worked 4 me.... good luck people....