The accuracy of the devices's position isn't the best when WiFi and GPS are competing.
E.g at my work the accuracy is 10 to 20 meters on WiFi (GPS is left enabled and is searching), when GPS finally sees some satellites and takes over the accuracy suddenly jumps to 70-160 meters. Just mentioning that the position gotten without GPS is in the right place on the map as well.
"enableHighAccuracy" is set to true as well in watchPosition.
Device: HTC One M7 running Android version 5.0.2.