Apple Watch Series 5 making multiple HR readings even when I am not wearing it. Giving abnormal RHR.

So my Apple Watch Series 5 (less than a week old) is reading heart rates (more than 20 abnormal readings) during the night when I am not even wearing it. Is this a bug? Has anyone else had this recurring issue?

I called Apple Support and they asked me to restart it and see if that sorts it out. This was yesterday after and now the following is the story of what happened after that:

Last night I took my watch off at 9.30 PM. Between 9.30 PM and 12 AM, it didn’t make any readings which is perfect. It was still on the table. I kept checking the health app on the phone and it showed no extra reading since I took it off. Then before sleeping, at around 3 AM, I checked the health app again and still no readings and put my watch to charge.

I am like great, maybe it’s fixed. Now today I wore it again at 11.30 AM and suddenly it updated the health app with resting heart rate data past 12 AM (again, I’d checked this before and there was no data there when I went to sleep) with readings between 12AM and 3 AM. This skewed my resting heart rate with an abnormal value of 130bpm. That’s crazy!

My hypothesis is that it just takes my heart rate through the day and extrapolates random values for my resting heart rate. I don’t if that’s even the case. I haven’t found anything on this issue on the internet. I could add screenshots but there’s no option here.

Please let me know if anyone else has experienced this or whether this is even an issue. Thank you !