Not a glitch [i]per se[/i]
[Firefox 120.0.1 (64-bit); NoScript extension, maybe some others]
When I load this forum listing (
https://www.plctalk.net/qanda/forumdisplay.php?f=2), the page loading process includes a security checky by "Cloudflare;" it sounds like everyone else is seeing the same thing.
At that point I sometimes middle-click one or more of the unread thread links, which opens them in separate tabs; I look them over, post my usual gibberish, and close them.
If I return to the forum listing tab and refresh the page (so I can see if there is an opportunity to post more gibberish), it yields a complaint about something and suggest I contact some administrator. However, if I click the browser
←[Go Back] button, then I get the forum listing, which can be refreshed without incident.
What eventually I noticed is that, when I originally opened the forum listing page (i.e. typically from a bookmark), it actually redirected to second page, although that page is essentially the same forum listing page. If, instead of refreshing that second page, I then click the browser
←[Go Back] button to the original link (likely from my bookmarks), then I can refresh that page without the warning.
Small potatoes, but the bottom line is that seems to be working okay, at least for my setup.