So I have my Unity game running fine on Windows with DX11 @ 60-80 fps. When I switched to Vulkan API my framerate dropped to the mid 40s. I started toggling effects, and when I toggled AmplifyBloom I saw the biggest improvement.
I know Vulkan in Unity is still considered "experimental", but I think you guys should look at your code and see if there is anything happening that might be causing more work for the Vulkan driver over the DX11 driver.