systemctl hibernate not write the contents of the RAM into swap partition or swapfile. le

Hello
I see that the systemctl hibernate command does not write the contents of the nvram in the swap partition (or in the swap file). This is also true in version 21.04

There is therefore no restart with the recovered data. Worse, when restarting, the partition is not in good condition. The FSCK command automatically repairs the partition structure.

I work around the problem with the sudo hibernate command which calls the S2DISK process, but it doesn't work if using a swap file and is only present for LTS versions!

Please tell me the correct method to use.

File systemctl.txt contains the traces of systemctl hibernate => you will see just ONE LINE for the hibernation action.
oct. 03 19:47:52 a kernel: PM: hibernation entry

File s2disk.txt contains the traces of sudo hiberntate == you will see the copy of the ram
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x00000000-0x00000fff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x00088000-0x000fffff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x20000000-0x201fffff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x40004000-0x40004fff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x94a13000-0x94a13fff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x94a23000-0x94a24fff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x94a32000-0x94a32fff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x959b0000-0x961affff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x961b1000-0x961b1fff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x961bd000-0x961bdfff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x97d3c000-0x97db6fff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x9a7bf000-0x9affefff]
oct. 04 12:17:20 a kernel: PM: Marking nosave pages: [mem 0x9b000000-0xffffffff]
oct. 04 12:17:20 a kernel: PM: Basic memory bitmaps created
oct. 04 12:17:20 a kernel: PM: Preallocating image memory... done (allocated 666109 pages)
oct. 04 12:17:20 a kernel: PM: Allocated 2664436 kbytes in 0.64 seconds (4163.18 MB/s)
oct. 04 12:17:20 a kernel: Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done

Thinks.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: hibernate 2.0+15+g88d54a8-1
ProcVersionSignature: Ubuntu 5.4.0-88.99-generic 5.4.140
Uname: Linux 5.4.0-88-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.20
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: Unity:Unity7:ubuntu
Date: Mon Oct 4 12:56:25 2021
InstallationDate: Installed on 2021-06-05 (120 days ago)
InstallationMedia: Ubuntu 16.04.7 LTS "Xenial Xerus" - Release amd64 (20200806)
PackageArchitecture: all
SourcePackage: hibernate
UpgradeStatus: Upgraded to focal on 2021-06-06 (119 days ago)