I've concluded that it's a HW driver bug after trying out creating swap file, adding resume device and offset to grub; even tried setting SELinux to permissive.

It tries to go into hibernate but immediately wakes up.

There are others in Fedora forum who have had successful hibernate with Zram & swapfile.

I didn't find anyone else with my laptop Asus ROG Strix Scar 16 (2023) with successful Hibernate either on our Linux discord.

Yet another reason why I prefer zswap to zram swap. When properly tuned, it's really great.