Bug (or bad feature?)
The game arbitrarily decides to use the GPU with more vram, as shown in the “warnings.log” file located in “Documents\My Games\Age of Empires IV”:
(I) [23:34:55.559] [000009108]: Adapter: NVIDIA GeForce RTX 3050 Laptop GPU video dedicated: 4184866816 shared: 14867206144 system dedicated: 0
(I) [23:34:55.586] [000009108]: Checking against Adapter: AMD Radeon(TM) Graphics video dedicated: 4267880448 shared: 14867206144 system dedicated: 0
(I) [23:34:55.586] [000009108]: Adapter chosen because it had more dedicated vram 4267880448 > 4184866816
In other words AOE4 ignores the settings in Windows Graphics settings:
In systems with two GPUs it might mean that there is no way to use the fastest GPU with AOE4.
Suggested solution:
AOE4 should rely on Windows Graphics settings like other games and applications.