It could also be the system you are testing on. If you are using a laptop with split display devices (an integrated plus a dedicated GPU), many mobile configurations don't yet pick up Vulkan very well and need to be manually enabled in order to best utilize that API. Otherwise, you'll be comparing an integrated display device trying to manage Vulkan and comparing it to a dedicated GPU running OpenGL. And the OpenGL on a dedicated GPU will do much better. So if Vulkan is running significantly worse/choppy compared to the 'basic' render mode, that is something to check.
To enable a mobile GPU for Vulkan on Windows 10:
- Type in 'graphics settings' in search, open the app by the same name.
- Make sure 'Desktop App' is selected in the drop down menu, then click on 'Browse'.
- Find the player in the folder for the project you are testing and select it.
- Then in Options for the app/program, select the 'High Performance' checkbox, then save.
From then on, you'll be utilizing any dedicated GPU for the app/program. If you're not running such a system, then this won't apply. But most of the time when I've heard of a similar issue like you reported, it has to do with the system's lack of detecting Vulkan to enable a dedicated GPU.