Moisture Observed on Video Doorbell 2 Lens

Ring video doorbell 2: Since October 21, 2020, I have noticed by VD2 has moisture (fog) on it. I wipe it off and it’s okay until the next morning and I have to wipe off the moisture again. What is the cause and corrective action to prevent the moisture from recurring? PS, my back door VD2 does not have that problem.