As it is clear from the subject, this is the nature of my problem. As a long time member (almost 6 years), I made the decision, I should report this further. To be more precise:
1. ACTIVITY score (as seen in the Profile, My posts and other sections of the WOT site):
According to my observations, this number has remained THE SAME for many months. The number 4682 has not changed for AT LEAST a couple of months (very likely much more time has passed without any change), ALTHOUGH my rating habits have not changed dramatically for a long time.
For example: For AT LEAST 6 months I've been rating websites more or less consistently. With this I mean:
Sometimes I make only a few ratings per month, but in other months more than 20 per month. But in each of those 6 months I rated at least few websites. Almost each month I also make at least a few scorecard comments. The ratio is now roughly 1 to 3 (one comment on three ratings, though this ratio varies greatly each month);
2. My (official) number of ratings:
In REALITY, there are EXACTLY 646 ratings I made until today (15.11.2016). This is the OFFICIAL number, that changes (increases) instantly I rate a particular website and I can check the number under the section "My ratings".
Only in November of 2016, until the 15th (and the day is not over yet

I know, that sometimes it takes time, that the changes become apparent, but now so much time has passed, that I'm almost sure that there is something wrong.
So for the end, everything SUMMARISED:
I can just hope, that someone will look into the matter further, because this "bug" (or whatever it is) has now become much more than a simple annoyance, because the discrepancy is simply too big (646 versus 555 ratings - that is more than 90 ratings, or put otherwise, around 15% of ALL my ratings) and my ACTIVITY score (4682) remains the same for more time I can actually remember, though NOTHING of importance (MEANING: regarding how much and in which way I use WOT) has changed from my side.
Regards.
Denis
P.S.
I have screen-shots (if perhaps needed) to prove, that this actually occurs as I described and another reason is, that pictures tell more than 1000 words
