This is a classic example of misinterpreting data without a proper knowledge base.
The reasoning behind the moon cycle theory is because of the hormone melatonin. Melatonin helps regulate our cycles and even the onset of menopause. Melatonin itself is regulated and altered by light, both natural and artificial, including the blue light emitted from most electronics.
In order to actually test if it’s fact or myth, you would have to only use data from before the invention of electricity.