Never encountered it once in thirteen years of using CloudFlare. If it did happen to me eventually as a one-off freak occurrence, that's a temporary fringe event.
If it is happening to the commenter continually throughout CF's network then I'd say that's probably their problem. Frequent or consistent? Well, it's probably the user.
I have this problem, happens for perplexity.ai too for example... I never had issue until two months ago, and now I'm locked out of some quite interesting websites
If it is happening to the commenter continually throughout CF's network then I'd say that's probably their problem. Frequent or consistent? Well, it's probably the user.