I got the same exact experience too a long time ago with Ubuntu 18.04 LTS but on a Ryzen 5 1600 with a Nvidia GPU. It might occur in Manjaro too, but I think it should occur less frequently than in Ubuntu due to the fact Manjaro has newer kernel versions.
Manjaro froze on me only twice in the first couple days since installing it last February (back when the latest kernel version was 5.3), and I did the following to basically eliminate them:
- Set the kernel parameters
processor.max_cstate=5 in grub
- Install zenstates from the AUR and create a systemd service to run
zenstates --disable-c6 at startup
It's worth giving those a try should Manjaro freezes on you. Have fun setting up your system!