This is interesting.
First off, Seagate tends to vendor-encode a lot of their attributes (see 0x01, 0x07, 0xBE, 0xC3, etc.), so reading them literally is always tricky. I'm not familiar with this exact model of Seagate disk, but I find it's behaviour questionable. I should, however, be fair: I have a lot more familiarity with the behaviour of WD drive firmwares; Seagate does things quite differently in a lot of regards, and I don't have as much experience with their drives.
Attribute 0xC4 is supposed to track the number of times any LBA remapping occurs (whether successful or failed). For successful remaps, 0x05 should be incremented. For unsuccessful remaps, I'm used to seeing 0xC6 increment as well.
So, basically, attribute 0xC4 by itself does not really shed light on what transpired with this drive regarding actual remaps. It may be that previously during the drive's lifetime there were numerous LBAs which were considered "suspect" and marked unreadable (which increments 0xC5), then upon later analysis determined them to be usable/fine (thus no remaps occurred, and therefore 0xC5 gets decremented). In the latter case, it's very possible the drive could be experiencing this issue repeatedly across the same set of LBAs.
HD Tune Pro does not have support for reading SMART GP logs (including the SMART error log) so I can't tell if anything is there; smartmontools can do this.
My guess is that the drive has marked, in the past, some LBAs as "suspect" and then upon further analysis determined that they were fine. When an LBA gets marked "suspect", it becomes unreadable (i.e. returns an I/O error to the controller, thus the OS). In certain situations this could cause complexities at the filesystem level. I can tell that the drive historically has had some complexities in reading data off the platters (attribute 0x01 shows that, but you have to go off of the normalised/adjusted values and not the literal), but that doesn't act as proof of my theory.
The drive also has a shock sensor installed in it, and I see that during its lifetime it's incremented 3 times (or possibly 2, as I've seen this attribute come out of the factory set to 1). This drive is 2.5" and installed in a laptop, which makes the likelihood of this sensor incrementing fairly high (placing the laptop on a desk firmly while the system is powered on, for example, can do it).
Has this laptop experienced any physical malevolence, such as being dropped, tilted to let fall flat on a surface (desk, etc.), or been shaken while powered on?
Have you taken the time to run
CHKDSK /R C:
(assuming the drive in question is used for the C: partition)? If not, please do so. When the system tells you to reboot, do it. During the reboot you'll see a blue screen where the drive is checked for errors, as well as read every LBA associated with the filesystem metadata. Note that
, so issues should get repaired (hopefully).
If you've tried this already, then my general advice would be to replace the hard disk just as a precaution. Whoever the vendor of your laptop is, make it their problem -- they can do an RMA/replacement for you.--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.