Unusual low Resting Heart Rate Reporting

I’ve been getting since April 19th a very low Resting HR reading (around 33) when it used to be around 55.
My Apple Health data shows that it should be around the 50’s so I don’t get from where is this low value coming.
I’ve tried to manually overwrite it (in daily data) and Setting but keep to the 33 ish value.

Now it seems to have go back to normal values (April 21st)