Link you followed has expired — intermittent issue

Hi,

When our client tries to publish a blog post using Firefox or DuckDuckGo on his site (https://www.petcamp.com/blog/) he gets a “link you followed has expired” error. The post could be empty — no text or images or have a reasonable amount of content. If he uses Chrome, it works fine. We turned on all of the logging in the wp-config.php page and asked him to save a new blog post. It didn’t trigger any errors. We’re stumped. Any ideas or help would be greatly appreciated.

Thanks!
Lisa

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