Determine correct location for devices with no GPS?

Hello.

I have two nodes both Heltec V3 based - one solar powered is mounted on the side of the house, another portable. I wanted to use the portable unit to track the correct position when hiking. I presume these nodes do not have chip GPS built-in and they rely on a mobile phone to get the coordinates. But, the position they are showing on the map is hundred meters away from my position. I wonder if it can be corrected in the settings?