I had this problem a few weeks ago as I am running quite a few accounts too. What I did was give them a rest for a week after having confirmed them, then I warmed them up again. To warm them up I was EXTREMELY careful and gentle. I first had the accounts only view stories, around 20 a day, and not like or follow anything. then after another week I had them start following around 20 accounts a day, then I increased it by 5 followers after every 3 days. After a week of that I started reposting content again and started making it like only pictures from current followers and nobody else, no more than 50 likes a day. Everything is running smoothly currently and I haven't had a single PV or Email verification, or even action block since. Just be patient and take your time, and make sure you make the account look like it is being run by a real person. Ramp everything up gradually and things will be fine.