(Or: The sad state of Apple’s Boot Camp support)
If you use Boot Camp with the official AMD GPU drivers the Boot Camp assistant installs, you’ll notice that many recent games in Windows 10 will issue warnings about outdated AMD GPU drivers and/or will simply crash (e.g. after a couple of minutes, like Forza Horizon 4).
Apparently, the only remedy is installing unofficial AMD drivers from https://www.bootcampdrivers.com (kudos!). It worked fine for me ( Adrenalin 19.1.2 V3 on a 15 inch MBP late 2018 with an AMD Radeon Pro 560X) – the games stopped crashing – BUT apparently, installing unofficial drivers from the above web site happens to void your Apple Care warranty (read: You do it at your own risk).
This means that one has the choice to either void the warranty or stick with an unacceptably buggy Boot Camp installation. Really, Apple?