All RX 400/500/600 and Vega GPUs doesn't have full AMD Support anymore with regular AMD Drivers. They now have limited support which means that they may get AMD Driver updates but not as frequently as the fully supported GPU cards.
Plus many of today's latest games uses technologies that the older 400/500 series GPU cards doesn't have.
So you will need to wait to see when AMD will have a newer updated AMD driver for your GPU card.
You can try a Modified AMD driver, at your own risk, from here: AmernimeZone Modified AMD drivers
NOTE: Look at the game's GPU Minimum requirement to see even if your GPU card meets the minimum or not.
You can find out which games your AMD driver and GPU card and PC hardware supports by going to a gaming site with a "CAN I RUN IT" feature like:
System Requirements Lab.com - Can I Run It
Game Debate - Can I Run It
PC Builds - Can I Run It