SOLVED. Update of kernel to version above 5.14 solves the problem! In my case I check version with uname -r and update kernel via Ubuntu mainline kernel installer. Important is to disable secure boot in BIOS. Next thing is that, it is safer to not take a try with highest kernel version, because of some dependencies problems. Thus I decide to install 5.15, whereas 5.16 was to high for me. Every step can be easily googled. More detailed hints can be found here: [URL]
Dear all.  I have got two the same Dell Vostro 5515 (AMD Ryzen 7 5700U with Radeon Graphics 1.80 GHz). On both I install official Ubuntu 20.04 LTS distro on new created partition next to build in Windows 10. Both have the same symptoms: both dies totally after suspend - Only hard reset can turn back my laptops to life (plug out everything, screw up the bottom chassis, plug out the battery and hold on for 30 seconds power button). And I am totally aware saying "dies", there is any, totally any contact with them. Its some kind of nightmare. I have install in the same way Ubuntu on X different types of machines (including Dell ones), and it always works perfectly. I was, and I am now, totally aware of every step I take during the Ubuntu installation and I am not able to point out, what is wrong. It must be said that on Windows I do not have this issue. Furthermore - I perform experiment, on both I perform two kinds of installation - minimal, and full (including third party software). Result: Ubuntu Suspend kills my laptops in the same way.  Can I please any clues and help on that - did anyone have similar issues? All the best
Dell Vostro 5515 with Ubuntu 20.04 dies after suspend