Finally found a solution for this issue => you have to add the kernel parameter "resume=UUID=<UUID_OF_SWAP_PARTITION>" to the /etc/default/grub file: edit the file and afterwards sudo update-grub) or use Grub Customizer.
Questions:
1. Why the heck is this kernel parameter suddenly required in Ubuntu 18.04 ?
It was definitely not necessary in Ubuntu 16.10, 17.04, 17.10. No, it wasn't, on 3 PCs !!!
2. Why the heck is this kernel parameter not set automatically if it is required ?
It should be definitely set automatically. Would make everything easier for a simple user like me :-)
Finally found a solution for this issue => you have to add the kernel parameter "resume= UUID=<UUID_ OF_SWAP_ PARTITION> " to the /etc/default/grub file: edit the file and afterwards sudo update-grub) or use Grub Customizer.
Questions:
1. Why the heck is this kernel parameter suddenly required in Ubuntu 18.04 ?
It was definitely not necessary in Ubuntu 16.10, 17.04, 17.10. No, it wasn't, on 3 PCs !!!
2. Why the heck is this kernel parameter not set automatically if it is required ?
It should be definitely set automatically. Would make everything easier for a simple user like me :-)