Is anyone else having problems with a changing IP address?

The binding of IP addresses to Geography is lucky happenstance that is not legislated or mandated.  It is generally offered as a third party service by companies such as Maxmind, who make an effort to maintain their mappings for use by other companies.

The reason it mostly works, is that companies are allocated IP address ranges and generally those ip address ranges are associated with an internet access point somewhere on the globe.  The IP address allocated to your region of Connecticut  has been assigned to t-mobile.  Perhaps t-mobile moved it from Puerto Rico to Connecticut, or perhaps the geo-location vendor mapped in incorrectly. 

If it matters to you, contact the webmaster of speedtest and find out who their geolocation provider is.  Then contact that vendor to let them know of the incorrect data.

Mike