Reading around a bit, it seems this happens on more MTK phones. It also appears to be a combination of MTK phone and carrier, and can appear suddenly. There are a couple of suggestions that making some changes in engineering mode makes it go away until a reboot. I can’t verify anything of this, nor have I found an explanation as to why this would work, but if you want try this at your own risk: open the phone app and type *#*#3646633#*#* into the dialing pad to start engineering mode. Scroll right to the ‘others’ heading, select SWLA, tap ‘Assert Modem’ and finally tap ‘Enable Software LA’ - there will be a network disconnect and reconnect. You may then also need to disable and re-enable location in the general settings.