Nexus 5X - Fingerprint hardware not available

Hi,
So I've been on holiday in Croatia with quite extreme heat. The phone got up to max 50 degrees centigrade, but I never noticed any issues. Until yesterday, the phone was working fine as far as I am aware, Nexus 5X and 6P have known overheating problems. I noticed the fingerprint sensor wasn't recognizing my fingerprint so I deleted it and I re-calibrated and cleaned the sensor and the finger I was using. I had successfully added the fingerprint and it would still not recognize it. I updated it to the latest August 2017 Security Update, and that's where things went downhill. The phone became unresponsive, laggy, the screen would unlock and jump around on its own, and then when I used the fingerprint sensor I got the error:

"FINGERPRINT HARDWARE NOT AVAILABLE"
I reset the phone to factory default and it started to work, but i had to use a specific part of my finger, it was not working for other peoples fingers and I'm not sure how to fix the issue.
I bought this New on eBay because the Box was opened but phone was wrapped in Original Plastic and never turned on. But Google Support and LG want nothing to do with it as the warranty is void due to the third party seller.
Any Suggestions?

Thanks,
Luca

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