I have been noticing this for a few months, Norton 360 when VPN is turned on drains your iPhone battery all the time. More than 50% of the battery consumption all the time is by consumed by Norton. Also I don't have SMS protection enabled. I will try disabling VPN from now on as I don't want to charge my iPhone every day just because of Norton and see if things will improve. I have attached a screenshot below:
iPhone 12 Pro Max with the latest version of iOS and Norton 360
Norton please fix your software!!