Wifi network randomly pinpoints me as in three locations other than where I actually live

We just moved to Harpers Ferry, WV. We had Xfinity home internet installed on Friday, using the comcast-provided gateway. There seems to be some problem with how our wifi network is configured though, because every single device we have connected to wifi bounces back and forth between seeing us in Harpers Ferry (correct!), Charles Town, WV (nearby but still incorrect), White House, TN (more incorrect), and - less frequently - Quebec City (super incorrect). This is reflected in Google products and services and Apple products and services. Friends and family see me as being in TN or QC when using "Find My" on iPhone. Our HomePods think we're in TN and report the weather conditions and time for TN. If I google "restaurants near me" it'll give me results in Canada. I could go on.

I have read the thorough responses posted by @EG when other people in this forum asked similar questions. I was specifically looking at this post most recently, as this summarizes my exact same situation pretty well: https://forums.xfinity.com/conversations/your-home-network/router-indicating-wrong-geographic-location/61d0c361e41a4a46af42b441

When I try to report my correct location on those links though, it's interesting - all my IP addresses are coming up as the correct location, so those services are saying "sorry, can't do anything, we already have this correct." But there is clearly something buried somewhere that is reflecting a geolocation of TN and/or QC that is coming up intermittently.

At my wit's end and getting nowhere with Xfinity reps - none of whom seem to actually even understand the problem - I've scheduled a service call to have my gateway device replaced. I'm hoping that with the new device and a new MAC address, it’ll potentially never have been used before and not associated with any previous customers/locations. That's the only thing I can think of - that the 3rd party location databases are associating my device's identifier with an old physical location/address.

What are the odds this will actually fix the problem? If I bought my own modem/router combo brand new out-of-the-box, would this issue be solved? I don't know what to do and it's driving me bonkers.