Why is my geolocation tool sometimes acting like a drunk pigeon?

hey everyone, running a web tool called "What is My Location? - Find Your Current Coordinates & Map". it's been pretty fun building it out and seeing folks use it to find their spot on teh map.

• The Good Part: most of the time, it's spot on, users genuinely love finding their exact location and coordinates. the core functionality for basic geolocation accuracy works great for most desktop users, which is awesome.
• The Head-Scratcher: sometimes though, especially for mobile users, the accuracy kinda goes out the window. it'll show them literally miles away, like in a completely different city or even country. it's kinda embarrassing when teh map says you're chilling in the middle of the pacific ocean when you're clearly on land. it's like my app had one too many coffees and just decided to guess.
• My Question: what are some common, practical reasons for wildly inaccurate geolocation data on web apps, particularly with mobile devices? and how can I consistently improve this geolocation accuracy across different browsers and devices? are there specific browser APIs, like maybe the Geolocation API with some fancy options, or fallback methods (like IP-based lookups with a good database) I should be using more effectively?

help a brother out please, before my app starts telling users they're on mars.