Thank you for reply.
I had assumed that the cuda package was not useful for gaming so I had left that out. I shall keep that installed then. Unfortunately updating to 525 and installing the xorg-x11-drv-nvidia-cuda package did not help. Still low FPS after reboot.
I then checked the nvidia-gpu-firmware and indeed didn’t have it installed, odd. I did both reinstall linux-firmware and installed the missing nvidia-gpu-firmware package for good measure. Rebooted, but didn’t help. Still low FPS.
But, finally after switching to use the Nvidia GPU primarily as per your instructions. The issue did resolve. No more low FPS. It also provides even better FPS than before. 
Unfortunately this may have negative impact on how long the laptop can run on battery, when not plugged in. But still at least that horrible FPS is gone now. Thanks!
Note on the kernel version, I do have 6.0.15 installed, please check the inxi output. Perhaps you saw 6.0.8 in the dnf list installed output instead?