Freeform 3.11+ introduced changes to how its front-end scripts are inserted into pages (as static URLs). If you have server rules applied to JS and CSS files, you may run into issues. If this is the case, please upgrade to Freeform 3.11.2 immediately, and then switch the behavior back to previous approaches ('As Files' introduced in 3.10 or 'Inline' as it worked previously before 3.10+). This is a new 'Freeform Script Insert Type' setting available in the General Settings of Freeform 3.11.2 or with Project Config as `scriptInsertType: files`.