Wrong VkQueue provided to vkQueuePresentKHR in QVulkanWindowPrivate::endFrame()

According to spec:

https://www.khronos.org/registry/vulkan/specs/1.1-extensions/pdf/vkspec.pdf

VkResult vkQueuePresentKHR(   VkQueue queue,   const VkPresentInfoKHR* pPresentInfo);

• queue is a queue that is capable of presentation to the target surface’s platform on the same device as the image’s swapchain.

problem in your code is in line:

err = vkQueuePresentKHR(gfxQueue, &presInfo);

should be:

err = vkQueuePresentKHR(presQueue, &presInfo);

Probability that gfxQueue will not has capable to present something is very low but not equal zero.