Email Confirmation Loops Lots of accounts

Hey everyone, I run close to 400 accounts, datacenter proxies, 2 per per proxy, and between 40-60 accounts everyday are in an email verification loop. Some clients say they received no email from IG, others did and accepted login attempts. Regardless Massplanner keeps saying email confirmation. Then I tried to tell them to change their passwords, turn two factor on and off, still no luck for most accounts. Most of them are on the verge of cancelling, any thoughts? I’ve had 4g proxies(20 of Henry Cooper’s to test) And it didn’t make a difference, still was stuck in the loop. Any help greatly appreciated.