Email engagement drops for interactive content, tracking or deliverability issue?

Hi everyone,
I’ve been running a few email campaigns with interactive links and noticed that open rates and click-throughs don’t always line up with what users report. Some recipients say links don’t load correctly or are flagged by their mail clients, which makes it hard to tell if it’s a deliverability problem, tracking setup, or content rendering issue.

I’m testing this with a simple spelling game website flow to see how people interact from emails to a web page, but the results still seem inconsistent. Has anyone using phpList seen similar behavior, and do you usually start by checking tracking pixels, link rewriting, or spam filtering rules?