'issues' is a loaded word, it tends to make people think there is a problem. There is no problem per se, its PoS based so you get rewards in line with your staking frequency, in any mature PoS system small holders have to wait a long time. Fortunately there are a few community run pools to help newbies on their journey. The devs are also working on a potential demand-based payout, the user withdraws research rewards when they want to.