Hi there, welcome to the forum.
Please always provide your garuda-inxi, as required by the template.
I’m not an nVidia user, but I remember (and easily found with a forum search, I hope the dGPU model is the same as yours) this long battle:
Probably reading it in detail can lead you to the solution without repeating the trials in that thread.
Basically you need to remove the nvidia-390 stuff including dependencies (check also the mhwd -r steps), install the nvidia-470-dkms package and you should be good to go.