How did this ad end up on my Instagram feed?

I consider myself to be pretty switched on when it comes to privacy, although I’ve began caring less and less as my attention is spent on other things… Maybe I slipped to far, because last night I was browsing a website looking for a Human Machine Interface from 4d systems (a relatively niche product) Today, it’s the first ad that appears on Instagram. Any idea how it got there?

1. Searched for it via DuckDuckGo, in safari on OS X. (Signed into Instagram on that browser, and fake Facebook account which shares no info with said Instagram. Fake facebook account signed in on same iPhone as Instagram. 2. Instagram and fake Facebook settings have fully disabled all tracking and ad personalisation settings that are possible. 3. I actively engage ads I don’t care about, and often receive ads for COMPLETELY irrelevant things, I find this fun.

How did within a matter of hours this HMI end up on my Insta feed, I’m sure I’m missing something obvious… surely not cookies…

Someone shared, or bled data. 4d systems webpage? Likely - but they don’t know anything about me… AdGuard and safari - couldn’t be a cookie? duckduckgo? Doubt it Safari? I thought safari blocked cross site tracking?