I’ve tried clicking on the triangle but I don’t think that’s a button. I could only get a black page if I accidentally clicked on the button which shows a preview of your draft. But if you’re writing something it shouldn’t be a completely blank page
Found the problem. I have Cloudflare in front of my site and for whatever reason it has started to present a javascript enabled Challenge page when requesting drafts.json
[Specifically I think this was caused by the Cloudflare WAF feature using the Cloudflare OWASP Core Ruleset]
I cannot reproduce this, Chrome Windows 11 & Chrome Android 13. Both versions of the triangle cannot be clicked. However, on mobile if you push the icon, it opens a blank preview.