No, no VPN. Nothing different in fact than a few days ago when I installed iOS 11. It just started doing this two days ago and continues now all the time. You can also see that in battery usage Safari appears at the top all the time now, consuming about 40 of the battery life used at any point in tims. Definitely some runaway process. I'm not too fussed over it. I'll wait until the next update and see what changes. From there I will start aggressively reporting bugs.
Check the battery settings to see whether or not the usage and standby information are identical. If they are then you have a rogue app or setting.