Refer: https://www.dell.com/community/Inspiron/Suspend-resume-problems-on-Ubuntu-18-04/td-p/6072410
Re: Suspend-resume problems on Ubuntu 18.04
It is the buggy nouveau driver again. That's what solved the issue for me.
Edit the file /etc/default/grub.
$ sudoedit /etc/default/grub.
Add "nouveau.modeset=0" to the line that says GRUB_CMDLINE_LINUX then press ^O to save the file and ^X to live then run.