22" tire vibration

[intimidator01238]

I have a set of GM 22" rims with Bridgestone dueler HL Alenza Plus tires on them. Ever since I bought them I've been having a vibration between 40-50mph after the truck sits overnight and especially when colder. Have brought them back to be roadforce balanced and that didn't fix it. Started to think I was having torque converter issues the way the truck would shake but it would only do it for a little until the truck was driven a bit and then it'd smooth out. Finally put the original 20" wheels back on over the weekend and no more vibration. Smooth as glass. I'm thinking now that for some reason these tires get flat spots easy just sitting overnight. Anyone else have that problem and what did you do? I was thinking about calling Bridgestone but I doubt they'll give me the time of day. The tires only have around 4,500 miles. Can't stand driving it with these tires if they're going to shake the truck like that every day until the flat spots go away.