I have been getting advertisements that are extraordinarily similar to my recent web searches and it is concerning
A few days ago while browsing casually, I came across a company's website which is well known for its products (at least in my country) and the very next day while I was reading some answers(which were unrelated to the Company and it's products) on quora on my other android device, I saw an advertisement/promotional link that took me to a post of that very company where it discussed about those specific products that I was looking at. This was not the first time, I had similar experiences where ads shown were personalized enough to make me wonder if my privacy is being compromised, but I simply ignored all such encounters prior to the very recent one that I am mentioning now, I assumed they were just coincidence. I ensured privacy on my every device is at its best and hardened them. Here is some hindsight about my browser and my devices.
1) I use the latest version of firefox with ublock origin, decentraleyes and cookie autodelete.
2) I am not on any social media including whatsapp, facebook, skype, instagram and also youtube(I do not watch youtube at all, thereby there is no data that could be used for showing ads)
3) I do use a gmail account, it is primarily due to school but I strictly limit it for that single purpose, (I tried to find a alternative for it but a lot of essential services use this gmail account)
4) Linux is my main operating system
5) The android device that I (rarely)use, has signal and duckduckgo browser.
6) I leverage on open source software and strictly avoid anything that is closed source
Could there be any loopholes in my setup that led to this?