The Geolocation libraries phone home to MS. They conform to the API outlined above and will use all permissible location data.
MS has a big SQL Server distributed DBS which has data about you and yours written into various tables including devices, IP addresses, various MAC addresses, Motherboard FCCA certificates, SLIC and UEFI data, Software and licensing states (activated or not! - I discovered recently), IMEI information, your mobile number, alternative email addresses, MSA , Store Purchase history, and so on. It checks back up on you on occasions, asking you to verify your Microsoft account - you may use an alternative email or your Windows ( Android or I-) phone, which also probably syncs to your MSA. You have a choice, except when you use a Windows phone. Your Photos may sync to your OneDrive too.
You can see a little bit of it by visiting https://account.microsoft.com with your MSA as your logon, unless you already signed in to your live account.
The GPS is not the only way to track a mobile phone.
It triangulates between phone cells all the time, just to see which is the best network signal. The position of your phone at any time is stored in a database, and can be tracked forensically to show where your phone was, when switched on, at any time. The cell information tracks your phone, and the densest tracks identify where and when your phone was located.
Sometimes (like, er, all the time in your and my parts of the world) your phone will be able to stumble upon signals from WiFi access points and hotspots, which broadcast their MAC and signal strength, identifying the location and this can be identified with data stored on yet another set of databases, despite the phone not actively using WiFi, it listens in case it needs to connect to it and for location data, which is passed back to combine and increase the precision with any GPS and cell position data it may have. It does not keep all this data, it phones home, and uploads it to the databases at intervals.
When Google drove around your neighbourhood taking pictures of the streets and real estate, it was also recording WiFi signals and mapping them too. Google Gathered Public WiFi Data For Maps, Connecticut Attorney General Says
Your ISP also maps all its hotspots, if you are still with Optimum: Optimum WiFi Hotspots Map| Optimum If you have moved on your current ISP does similar exercises for its customers, e.g. XFINITY WiFi Hotspot Finder perhaps. Even if there are not hotspots in the area most domestic and commercial wifi installations broadcast their BSSID information. Even the mass transit systems have Wifi don't they?
Still not convinced? Oh well, I tried.
If you try and log in from an unfamiliar system, you will usually be asked for verification. Even Yahoo does this. How do they know - well they don't, but they ask anyway if your location is not recorded on their Database.
I'd agree with your statement about Firefox, but I can't say that duckduckgo is a favourite for me in terms of retrieval. I don't share quite the same Weltanschauung about security as you do. For instance, I cannot see the point in not sharing location data, when I want to know what an accurate weather forecast will be for me where I am, so long as the app will also forecast the weather for me tomorrow when I will be in London. If it's broken in the "on" position, that seems good to me.
The Microsoft problem for you may have something to do with your IE 11 problem, or just incomplete registry entries/Missing Group Policy switches like the problem that broke Windows Photo Viewer for some: Is Windows Photo Viewer gone? - Windows 10 Forums It will be fixed in fairly quick order I imagine.
What is worrying is that Organizational leaks due to some disgruntled employee / crazy person / freedom fighter /terrorist can happen, and even worse, data can be illicitly sold to some deep pocketed nation, or multinational organization, who can use the data, without the controls that we thought we once had. Then perhaps we shall all be compromised. However, in the end it is Microsoft's data and intellectual property, and not ours, even though it personally concerns you and me.