Aggressive ad blockers are often the cause of many “site doesn’t work in Firefox” issues. When the Firefox user then loads the site in Chrome, it works because

Aggressive ad blockers are often the cause of many “site doesn’t work in Firefox” issues. When the Firefox user then loads the site in Chrome, it works because the user doesn’t have an ad blocker installed in Chrome (because they don’t typically use Chrome) or their ad blocker hasn’t updated its blocklists recently.