Unable to track my lost iPhone on Find My

Someone likely took your phone and either turned it off or put in a Faraday bag to prevent it from being tracked. There are some really bad people out there. The sad reality is most lost phones are never recovered.

The first thing I'd do is contact your carrier and ask them to blacklist the phone so it can't be connected to another network. Also be advised that Apple doesn't get involved in lost or stolen devices, you'll be advised to log into your iCloud account and put it in lost mode. Thieves are very clever and may send you messages purporting to be from Apple asking you to validate your credentials to prove you own the phone. It's a scam. If you respond to them, they'll take over the phone. As long as Find My was enabled, it's passcode protected, they can never get into the phone.

See what to do here --> If your iPhone or iPad was stolen - Apple Support

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