Alright, so I tried a bunch of stuff, essentially started my machine from scratch, and I know what the issue is.
After I installed manjaro kde I noticed grub was working when I rebooted. Ok, thought maybe I fixed it.
Everything was fine until I installed the 430 hybrid bumblebee drivers. That brought the issue of the grub menu instantly freezing back. Uninstalled them, grub worked.
Used auto-install proprietary and it installed hybrid prime 440... issue is back. Uninstalled those, grub still freezing.
Timeshifted with reinstall grub option. The timeshift had bumblebee installed, uninstalled again... still freezing. Something maybe lingering from the prime install?
Tried auto-install open source. Grub still freezees, but it was already so at best it didn't fix anything. Well not sure what to do now.