I experience long loading times and bad performance after a time playing Destiny 2 (1 hour aprox), the game run normal on startup but with time start the issues, i try lowering the Core Voltage on Afterburner and minimize the problem a little.
I back to 17.11.4 and the game perform normal, no load problems and better FPS.
Please fix your Drivers AMD
MSI RX470i5 6500
MSI B150 gaming m3
16 GB RAM