In fstab, I used this instead:
/dev/nvme0n1p6 swap swap defaults 0 0
I also had to do this (on 24.04):
https://community.frame.work/t/responded-ubuntu-24-04-and-hibernation-fw-13-12th-gen/51626/4
resume=/dev/nvme0n1p6 to the GRUB_CMDLINE_LINUX_DEFAULT line of /etc/default/grubsudo update-grub