Most repos recently updated without updating them

I’m using Gitlab for some years now and this never happened before: Most of my pirvate project repos, but not all of them, indicating a recent update. Most values are ‘4 days ago’ but some repos are stating ‘3 days’, ‘2 weeks’ or even ‘2 month’. I’m not 100% sure about the last one, but all other dates are wrong or at least not corresponding to when I updated them the last time. One other repo shows the correct date, since I really updated it yesterday.

How is that possible? Are there events that silently update all repos, maybe like the changing the password of the account? At first I thought maybe past due issues are performing some action that is handled as update, but not all repos have those.
Which actions are bumping the updated date? Is there a log? I don’t want to exaggerate, but would it be possible someone gained access to my account and, for instance, cloned all repos?

Here is a picture of the situation: