Triple-boot GRUB superblock problem

Question

I had a dual-boot system with Windows 10 and Ubuntu 18.04.1 and I wanted to try Kubuntu 18.04.1 as well.

So I've edited my partition table, created ~12GB for that cause, installed Kubuntu on it and my partition table looks as follows (I've also created a separate partition for my home folder in Ubuntu)

What followed is that Kubuntu's GRUB override Ubuntu's, it showed all the 3 boot options but from that point on I couldn't restart and boot from Windows to either Linux OSs or from one Linux OS to another without getting this error message

fsck.ext4 Superblock checksum does not match superblock while trying to open /dev/sdaX

As you can see in every reboot I get the (initrmfs) menu and have to manually fix the filesystem using this command e2fsck -pb 32768 /dev/sdaX enter reboot and go to the specific entry (mounted sda) that I fixed previously.

It looks like all 3 ext4 linux partitions Kubuntu, Root(ubuntu), Home(ubuntu) share the same superblock

roey@hpx360-13:~$ sudo fdisk -l|grep Linux|grep -Ev 'swap'
[sudo] password for roey: 
/dev/sda6  360892416 385613823  24721408  11.8G Linux filesystem
/dev/sda7  424935424 483340287  58404864  27.9G Linux filesystem
/dev/sda9  385613824 424935423  39321600  18.8G Linux filesystem
roey@hpx360-13:~$ sudo dumpe2fs /dev/sda6 | grep superblock
dumpe2fs 1.44.1 (24-Mar-2018)
  Primary superblock at 0, Group descriptors at 1-2
  Backup superblock at 32768, Group descriptors at 32769-32770
  Backup superblock at 98304, Group descriptors at 98305-98306
  Backup superblock at 163840, Group descriptors at 163841-163842
  Backup superblock at 229376, Group descriptors at 229377-229378
  Backup superblock at 294912, Group descriptors at 294913-294914
  Backup superblock at 819200, Group descriptors at 819201-819202
  Backup superblock at 884736, Group descriptors at 884737-884738
  Backup superblock at 1605632, Group descriptors at 1605633-1605634
  Backup superblock at 2654208, Group descriptors at 2654209-2654210
roey@hpx360-13:~$ sudo dumpe2fs /dev/sda7 | grep superblock
dumpe2fs 1.44.1 (24-Mar-2018)
  Primary superblock at 0, Group descriptors at 1-2
  Backup superblock at 32768, Group descriptors at 32769-32770
  Backup superblock at 98304, Group descriptors at 98305-98306
  Backup superblock at 163840, Group descriptors at 163841-163842
  Backup superblock at 229376, Group descriptors at 229377-229378
  Backup superblock at 294912, Group descriptors at 294913-294914
  Backup superblock at 819200, Group descriptors at 819201-819202
  Backup superblock at 884736, Group descriptors at 884737-884738
  Backup superblock at 1605632, Group descriptors at 1605633-1605634
  Backup superblock at 2654208, Group descriptors at 2654209-2654210
  Backup superblock at 4096000, Group descriptors at 4096001-4096002
roey@hpx360-13:~$ sudo dumpe2fs /dev/sda9 | grep superblock
dumpe2fs 1.44.1 (24-Mar-2018)
  Primary superblock at 0, Group descriptors at 1-3
  Backup superblock at 32768, Group descriptors at 32769-32771
  Backup superblock at 98304, Group descriptors at 98305-98307
  Backup superblock at 163840, Group descriptors at 163841-163843
  Backup superblock at 229376, Group descriptors at 229377-229379
  Backup superblock at 294912, Group descriptors at 294913-294915
  Backup superblock at 819200, Group descriptors at 819201-819203
  Backup superblock at 884736, Group descriptors at 884737-884739
  Backup superblock at 1605632, Group descriptors at 1605633-1605635
  Backup superblock at 2654208, Group descriptors at 2654209-2654211
  Backup superblock at 4096000, Group descriptors at 4096001-4096003

Which might cause a checksum error but on the other hand there was no problem with a dual-boot.

What is the problem here and how can I fix it ?

Thanks