Charge 5 not tracking heart rate accurately

[Seigniority]

My charge 5 has randomly started recording that my HR is more than double what it actually is. I’ve never had this issue before today, and I’ve manually checked my HR to be sure (I sometimes have palpitations etc). This morning, for example, it recorded my HR as 158bpm (at rest, sitting on the sofa) when it was actually 68bpm (manual count). Just now it recorded 146bpm (back on the sofa after going out) and it should be around 66bpm. It was running low on juice earlier, which I thought might be affecting it, but it’s the same at full charge now. The only other thing I can think of is that I cleaned it the other day, using cotton buds to get all the gunk out and antibacterial wipe afterwards. Any ideas?

Moderator Edit: Clarified subject

[MarreFitbit]

Hi there, @Seigniority. It's nice to see you around the Fitbit Community Forums. Thanks for bringing this to my attention. I'm sorry to hear that your Charge 5 is not tracking your heart rate accurately. I understand your concern, I will do my best to help you with this!

While reading your post, I was wondering if you're near a fan or something that generates vibrations? If this describes your experience, please note that your Fitbit device may display an erroneous heart rate reading due to the vibrations. In addition, keep in mind that there are some factors that can affect the heart rate readings such as movement, temperature, humidity, stress level, physical body position, caffeine intake, and medication to mention a few. For more information, see What factors can affect my heart-rate reading on my Fitbit device? 

[Seigniority]

Hi Marre, nothing in my surroundings, diet/exercise, medications etc have changed and it had never occurred before yesterday which ch I think it would have done if it were something to do with me or any vibrations.

I reset my watch two or three times, which initially seemed to work each time but would then revert to more than doubling my HR. At one point it was measuring my HR as 175bpm (which is in my max zone) when I was sat on the sofa and manually measured my pulse as 65bpm. 

Unfortunately it seems that my watch is completely malfunctioning, as it currently only shows a bright white screen when I turn it on, although it still tracked my sleep and is still tracking my HR. Because the screen isn’t working, I can only access that data on the app. I searched the website for repair options, but it seems that Google doesn’t offer repairs for Fitbit products, which is a shame.