I got into drones hobby a while back, before all these restrictions. FPV + small 250 build = fun.
But I live in NYC now and we can't fly basically ANYWHERE in the city. We have the strictest rules in the country. I'm cleaning out my closets and will probably ebay everything, except for my indoor FPV "woop" setup.
Update App. Update firmware. Do standard calibration (where you have to turn the drone in specific ways.) If it still doesn't hold position, redo calibration again, as it is easy to mess up. Chances are decent that this will solve your problem.