Can you please check if the GPS icon on camera will be green after mount the GPS mount in 1 ~ 2 mins. If not then it should be a non GPS mount.
You can also differentiate by weight. GPS mount is 18g and non GPS mount is 12g.
G-sensor will stop working. Since the A119 camera will be off automatically if vehicle is off as A119 is using capacitor instead of battery.
If you need it works, then you need to connect the camera with your car battery by a hardwire kit.
The focal length is different. One is 4.1mm and another one is 3.87mm. With long focal length, you can see further but the angle of view close to the camera will be small. You can see the following picture for reference.
Most of the mounts are universal for action cameras. With assembling the mounts to get it using on bicycle and helmet etc.
You can check the mounts name below for a reference.
It doesn't support to save the recordings as PIP for now. You can use some free tools to complement it.
https://superuser.com/questions/938458/how-to-put-a-video-in-a-corner-of-another-video
Please try to update it to the latest firmware from the following link. If it is not working, would you mind to open the case and check the ribbon cable if loose connection ?
https://support.viofo.com/support/solutions/articles/19000019600-viofo-a119-car-dash-camera-firmware