As I have never experienced this myself I dont have any verified solutions however if you search for "low GPU usage battlefield" or similar you will find lots of threads talking about this issues with many possible solutions. Just skip the threads where people have old cpu's bottlenecking the system since your system is very good.
Some things you can try is to mix up which directx version you are using and turn future frame rating on or off. If you are on dx12 now, try to switch FFR on and off and see if it does anything. If not, then switch to DX11 and do the same thing with FFR and see if it changes anything.
If that doesnt work then you need to to some search but some solutions involves making and set a future frame rate limit either in nvidia control panel or in battlefield console. Its the same as the FFR setting but you can control it better in console/nvidia control panel.
Other things is to make sure you have latest windows build, latest bios, latest drivers etc and that you do not have anything cpu intensive running in the background. I know some people have had issues with running shadowplay while playing. But this may end up in a troubleshoot effort for you unfortunately.