Hibernate AL on a dual-booting machine

As I had posted here, my older HP Compaq 6000 Pro AiO has some problem due to which its screen is gray w/ changing hues and vertical lines after waking from suspend. The double whammy though is that I am unable to hibernate either. When I issue systemctl hibernate, it does seem to hibernate. But on resuming, it takes me back to grub screen, and upon choosing AL (which is my first choice anyway), it just takes me to login screen and it is as if a new session has begun. There is no sign of the old session that was supposed to have been saved to disk. Is there anyone who can help me? Thanks much in advance.

Have you set up your system for hibernation as outlined in the ArchWiki entry for hibernation.?

I have not explicitly done so. I guess I assumed those are done already. I will go through that. Thanks.