Well, more info on this. After many fresh install experiments, able to reproduce with multiple machines, I'll be sure to submit a bug report. Currently no user end solution that I've found other than just live with the nouveau driver for Nvidia cards until another driver version is released that DKMS can compile and install properly.
Problem lies with the 430.64 drivers for GeForce 635 and later cards. Currently, the older version 430.26 works fine but if you want to upgrade to Kernel 5.5.6 you have to take the 430.64 drivers with it since the xserver driver, utilities, etc. are all tied to it. Doing this, DKMS can't do a successful compile on Kernel 5.5.6 after a reboot and thus reverts back to nouveau to at least get you to a desktop instead of a blank screen. I did try to download the latest drivers from Nvidia and register those with DKMS to see if it would work, but that also fails with some GCC compiler errors unfortunately.