Who I have the same questioned this topic

I have a Galaxy S10e and noticed today that 4 days into my billing cycle, I've already used 1.01 GB of data. In all of the last billing period I used a total of 1.71 GB so something is definitely weird. I dug into the Activity Log and noticed consistently there's about 100 Mb of usage early in the morning, around 7 am. At that time I am (1) sleeping and (2) at home so my phone is on my wifi network. And, I'm not using it at all because I'm sleeping & have been for the past several hours. So is the time on the activity log incorrect? If not, what on earth is my phone doing while I'm sleeping? And how do I stop it?