Hi,
I have a neighbor who is trying to track location of my device ( Pixel XL ) very accurately whenever I am at home. The neighbor lives in the flat below me. Wherever I take my phone, he tracks it accurately. Even if I power off my phone. How is this possible?

My phone is always on airplane mode. The wifi and bluetooth scanning is off. The only thing left is GPS which gives the physical location of the device. Since I can't remove the battery of my phone I cannot power it off completely.

I tried gps spoofing it helped the first few days but after a few days again he was able to detect it.
I have android 10 currently and rooted with magisk, I even changed the fingerprints of the phone to some other brand and device simulation.
How can a physical device be detected so accurately ( I know the distance is pretty close like within 100 meters ) but how?
Is my gps antenna sending out beacons ? Is my system compromised ?
I know he has a family member in the cops so might be using some device from the cops.
My device was connected to his wifi network previously so he has my MAC and device info.

I am finding a solution for this problem.

I noticed that where ever I took my phone I was followed. They are monitoring it day and night. Which ever room I go to. I tried putting it in the cupboard in the washing machine in the microwave oven they followed it accurately every where.
My question is the mechanism of tracking. What kind of a receiver can this be?
I tried checking for beacons for my phone using a Spectrum Analyzer with a GPS antenna but I couldn't receive anything.
I am related to RF MW field so it really is bothering me I want to figure it out how you can have such an accurate receiver.
One way to stop the detection is to use the Faraday Cage but then I wouldn't be able to use the device.

I know gps spoofing worked but when I do google find my device it keeps on coming back to the real location instead of showing the spoofed location using the mock location.
GPS spoofing works as long as there is no internet connection but when I connect to the internet ( that too using a cable ) they can start tracking again.

It looks like an RFID tag which they can read whenever they wish to in order to locate the device. Can it be related to NFC although I have switched it off too.

I tried checking my logcats but I couldn't find much ( not very easy to decipher ).
How can I verify if my system has been compromised? If I do a complete wipe and do a fresh install would that completely remove any intrusions if any.

How is it possible to track a phone so accurately.
Does the GPS antenna of my phone respond back to beacons even if its off?

Is there a monitor mode for GPS like we have for our wifi cards ( airmon-ng etc ).

Please let me know if it needs to be posted to another thread.

Thank you !