How can I fix Find My location fluctuating between accuracy levels?

I'm guessing there's more to this question that might at first seem.

First up, Location Services (which include Find My) has a 'precise' and an 'approximate' option, depending on how granular you want the location to be identified. You might want some apps to have only a general idea of where you are, and you might want other apps to be very precise.

There's no case that I'm aware of where the setting flips arbitrarily - it's either set to precise, or it's set to approximate, and you're in control of which one.

However, that said, the whole system is imprecise by nature. Find My relies on things like GPS to locate your device. GPS signals are great in open space, but often obscured in urban areas such as when surrounded by steel-and-concrete buildings, polarized glass windows, etc., which can block or reflect the GPS signals.

In these cases, the phone (assuming you're talking about a phone) uses an approximation model based on the last-known good signal, plus some offsets based on the internal accelerometer and compass (kind of like "I know I was right _here_ by this tree two minutes ago, but since then I've walked about 100 paces North-east, so now I expect I'm over _there->_

(Note: the reality is a lot more complex than that, with multiple signals and heuristics used when in a low- or no-signal area... this is just for illustrative purposes).

So, even if Precise tracking is on there may still be some approximation involved based on the environment and signal integrity. It's usually not much - a matter of meters, not kilometers, (or yards, not miles) but it does mean you can't necessarily pinpoint which seat in the theater someone is sitting at, but you know they're in the stalls somewhere.

Note that if you're trying to track some device nearby, most recent iPhone models switch to ultra-wideband (UWB) mode which is very precise over short distances, so that's what enables you to find your phone when it slipped behind the couch.

I can think of one or two cases

Either the phone's owner has turned off precise location, or the user is in a location with poor GPS signal and is relying on WiFi or cellular mapping as described in my earlier post.

Off-hand I don't know that you can determine which one is the current situation.