Why does Direct contextual advertising appear in Opera Mini for requests from DuckDuckGo on the desktop?

Question

contextual advertising

When surfing through Opera Mini on the phone in Yandex.Direct contextual advertising ( YAN ), I see offers related to my requests on the desktop. The thing is that on the desktop I use Firefox, and I enter requests through DuckDuckGo, which, although it uses Yandex issuance, does not merge the data (at least it declares this).
I use Google to search Opera Mini. In Firefox, I don’t use Yandex search either, I don’t have Yandex add-ons installed (I used them actively before, but deleted them some time ago - I was just trying to find out the source that was leaking data. Removing nothing, in general, did not change).
Not logged into Opera Mini in Yandex account, logged in to Firefox.
Both the phone and the PC access the Internet through the same access point.
UPD.While writing the question, I found in the settings of one of the FF add-ons a checkmark about displaying ads and information about access to browser history by a third party . Could this be the cause and sufficient condition for the situation described in the first paragraph?
UPD2. A few months later, I can say for sure: yes, the problem was in the Screengrab add-on - in the setting that transmitted data to the third party. And Yandex has already connected this, apparently, by IP (when the phone exits through the same access point) with sessions in Opera Mini.