You're using CDN and Image not showing when tweeting on Twitter?
I'm using wordpress and I've recently activated CDN on my site. Suddenly my twitter image stopped working on Wordpress. It took me two days to find out the problem is something very small. The solution is explained in this video.
Use Card Validator - Twitter to check if it's working.
https://cards-dev.twitter.com/validator
Important:
Make sure to clear all cache (including on cloudflare) to push through the change.
Make sure you don't Twitter in your robots.txt. Just add the following line:
User-agent: Twitterbot
Disallow: *
Allow: /wp-content/uploads/*
