u/Far_Anything_7458

I travel a fair amount both domestically and internationally. When I travel internationally I use my passport of course (USA) and never have a problem. When I travel domestically, almost every single time they have an issue with my drivers license. It's a Real ID license. Usually the initial TSA person has to call over a supervisor, then I have to go to another machine and finally they clear me, but what's going on? Should I just travel with my passport all the time?