Laptop can't go into suspend on normal kernel, but can with fallback. (and other problems)

Ok, so here are the problems I have with my laptop.

First problem is that for some reason I can only put the laptop in Suspend(Sleep) only if, during the boot, I selected the “fallback” kernel (doesn’t matter if its LTS or not).
If, for some reason, classic kernel is selected with systemd-boot, next time Suspend is called will result in black screen (with backlight on) and nothing else (can’t change TTY using CTRL+ALT+Fx) so “power-button-hold” it is.

The other problem I have is that after waking from Suspend (usually for longer even if laptop is charging) the SDDM just decides to play Russian Roulette with me. Examples include:

  • Dies so i have to restart only SDDM,
  • Proceeds to do standard shutdown
  • Shows random @@@@@@@ symbols
  • Lets me login but after small amount of time freezes whole computer where I have to hold power button to turn it off
  • Works completely fine
  • Sometimes shutdowns partially (gets stuck somewhere with systemd idk)

Any suggestion with my diagnostics (since I don’t know how to do that really) is appreciated.
Main concern for now is the first problem, so thanks in advance for your time.

have you installed with swap (hibernate) disk space enabled?

I have Swap enabled but I disabled hibernation (both during installation and later by removing “resume=” kernel parameter which was causing some other problems I already posted and fixed on the forum).