Thanks, Joseph.
I'm no expert but I think the problem may point in a different direction – probably because I wasn't clear. When Maps calculates a travel time to or from "my home" it uses the location of my office. When a commercial website tries to find a source "near me" for a product, it uses the office ZIP code and finds me sources near that location instead of my home ZIP and location . This is always independent of my "present" location, i.e. wherever I am when I ask for the calculation; instead, it's just using my office zip code as a default "my location." I think this is all independent of GPS; it happens (not surprisingly) whenever I ask it to calculate travel time between my home location (not my present physical location) and any Point B.
I think the solution lies in changing my default location from the office address/ZIP to my home address/ZIP, but for the life of me I can't find where/how to do that.
Let me know if you can help with that, and in any case stay safe.