Came here to report exactly the same bug. Affinity Designer completely crashing the AMD driver at least two or three times a day requiring a full driver restart to recover. There's seemingly no pattern to it; Designer could be minimised and running in the background, having not been touched for an hour, and suddenly crash the system. Other times, it'll be as I'm actively working in it. The only constant is that Designer is open.
I'm on a Radeon RX 6800. Have tried every AMD Adrenalin version going back 6 months and currently running 22.8.2.
Affinity Designer is the only app that crashes. I can't enable OpenCL as it tells me my system is unsupported (says I need at least Windows 10 and I'm running Windows 11 - screenshot below). Have tried the WARP and Radeon 6800 renderers with no change in crashes.