I've been troubleshooting a strange issue on my site for about a week now and finally resolved it last night thanks to the helpful folks on Stack Overflow.
The issue was that on my last post about my first flutter app, I included a link for users to visit the app store page to download the app. The link worked as expected on desktop, but when I tapped it on my iPhone, my browser was redirected multiple times to shady advertisements like "Spin the Wheel!" "You've won!" and "Claim your prize now!" complete with countdown time, annoying colors, and blinky text. The address bar would be filled with garbled letters and numbers and was different each time. Video below shows an example of the behavior.
Some other odd bits. The advertisement redirect only occured when I 'tapped' the link but NOT for long press followed by selected "open link" and NOT for copy/paste the URL, open new browser tab, and paste. I tried resetting cache and website data and even went so far as to reset all phone settings. Same behavior persisted. My brother and I were experience the redirects, but none of my other friends who I asked to test. While I didn't connect it at the time, my brother and I are the only ones who actually commented on my site. So, thinking my website or phone must be hacked somehow, I headed over to Stack Overflow to seek assitance.
Turns out it was the Disqus commenting system that I had set up on my site (comes default with the Krabi theme). I removed Disqus from the website files, though did a little more testing and experimentation to discover that it IS possible to keep Disqus on the site and remove the shady behavior. In the Disqus site settings, under advanced, I disabled "Tracking" and "Affiliate Links."
Still, the whole experience was horrible enough, and the comment system not important enough to me that I will not be using Disqus anymore. I'm also going to recommend to this theme's (Krabi) creator that he not have Disqus enabled by default, or to provide more extensive documentation on how it can affect the behavior of the site.
[EDIT 5FEB] Stumbled on this post about all the garbage Disqus performs behind the scenes without your authorization (and even for paying customers!) - 76 http requests, 2MB of data, 11 third-party trackers.