I'm with latch66. I use Microscale's Micro Satin on the topside of my vehicles and Micro Flat on the tracks and wheels. I had this same problem with things turning white with Tester's Dullcoat, so I quit using it. Usually I noticed it if I tried to put on too thick of a coat at once or several coats too quickly. I think a satin finish on top is the way to go, Tony Greenland, author of
Panzer Modeling Masterclass, also uses a satin finish, but uses different products. Satin finishes help make your paint scheme appear more vivid and accentuates the detail. If you want to make certain areas have a flat finish, use pastle chalks on top of this. I don't use decals anymore, just dry-transfers, so I don't go for the whole; primer / paint / Future/ dullcoat thing either, which in my opinion, adds too much thickness to your finishing scheme and ends up obscuring your carefully built details.