Thanks, I see. I checked the report and sent a detailed answer in e-mail.
I also post the (partial) answer here, which may help users in similar situations:
I examined the status of the Seagate hard disk and as the software reports, the drive experienced some issues with the #196 Reallocation Event Count attribute.
Alone this issue is not a serious one (this is why the health is still "good"), just it means
that there were suspicious sectors on the disk surface which may require attention on the side of the drive.
Disk problems may occur often if it is combined with power line issues and
2.5" hard disks (like this one) may be more affected.
For these disks, it is always recommended to use a dual (Y) USB cable
as single USB cables (often shipped with the external drives/enclosures)
may not provide enough power for proper operation.
Personally, in this situation I recommend to check
section of the Frequently Asked Questions page.
This describes the recommended steps to analyse the hard disk, reveal and fix
any possible issues because the most important is to verify if the drive is
stable (there are no more, currently hidden problems).
These tests should force the drive to re-examine the suspicious areas,
reallocate the sector(s) if required.