Just bought a RX470 and installed the lastest driver, however I was unable to start any vulkan game and GPU-Z show that my GPU does not support Vulkan.
Use DDU and Windows safe mode. Uninstall the new driver. Then try an old driver. You can report this problem to AMD with that... https://www.amd.com/en/support/contact-email-form You can get older drivers with that... https://www.amd.com/en/support/previous-drivers/graphics/radeon-400-series/radeon-rx-400-series/rade... You can try 19.12.1 or older driver.
Which Windows version do you have installed?