the last several drivers have been problematic on R series cards. I suggest you return to 18.3.4 or earlier. A much older driver 17.7.1 was near flawless. It however is not updated for many new games. That doesn't mean it won't work with them either. You would just need to try. If it isn't broken don't fix it. Unless you need to update a driver I never recommend you do so. You should let AMD know their current drivers aren't working on your card. Email Form
These are user to user forums so you are not letting AMD know this here.