Gary Illyes from Google is back and this time he said that those "Checking if the site connection is secure" interstitials you see on some sites, some of the time, is the "last search-friendly things you can do."
This is a feature that CloudFlare, and other CDNs have, to help prevent spammy bots from hurting your server. Here is what the interstitial looks like on ChatGPT, where you see it a lot, but I've seen it on many sites over the years and I've even turned it on for this site for short periods of times during extreme situations.
Before you can access the site's content or page, sometimes you need to validate you are not a bot. Which is why I try to never ever have this message come up. In CloudFlare you can configure how strict you want this prompt to be and I keep it at the lowest level. But some sites do not and I guess for Google, it can cause issues.
Gary Illyes posted on LinkedIn:
You know those interstitial pages some CDNs inject every now and then before serving your URLs? They're supposed to check if the accessor is, by some definition, authorized to access that URL. Yeah, they're one of the last search-friendly things you can do.Here's how it looks like when I try to render a page serviced by a CDN that offers such protection. Now imagine what happens if all pages on your site look like this after rendering.
So do your best to never show this message, if you can. Sometimes your site is just being hammered by spammy bots and you need to do something to block them in the short term (including blocking rouge IPs) but most of the time you likely do not need this turned on all the way.
Forum discussion at LinkedIn.