I needed to reinstall 12.1.
During partition step, I choose to import the partition table as I used to do in this case.
For the first time I detected that the swap ( very small logical separate partition situated in the extended partition ) was not activated.
I detect this because it took long time to start or switch between apps.
This is not the first time I reinstall 12.1 on this box.
Apart from reinstalling, yoou could at least check if the entry in* /etc/fstab *fits with what you think your partitioning is. And you could check your dmesg to see if something goes wrong with respect to swap when booting.
And when you want us to look into your story, then please support it with computer facts like
If the swap partition is addressed by uuid in /etc/fstab (and the resume option of the boot menu) and it has been reformated during setup, then it won’t be found anymore until you edit these files. This happens often while installing several distros which share the swap partition (you don’t have to reinitialize swap, but sometimes it happens accidentaly or some setups don’t give you the choice).
I suppose that during reinstall process over the same system ( and unique system) installer does not check any of the two checkboxes “Format partition” and “Mount partition” in the “Edit partition device /dev/xxxxxxxxxxxxxxxx”.
While I knew that only partitions systems would be formatted , I have not verify what the installer had done after importing the existing partition table. So I did not see that the partition table will not be mounted.