I'm working on an application written in dHTML (HTML, CSS, JavaScript, and Perl/CGI) running under Apache and mod_perl on a Windows 10 basic PC. The OS and all browsers are up to date.

I have a CSS file loading animation. It runs as expected in an .HTML file in all browsers I test in (Chrome, Edge, FF, IE, and Opera). It won't run at all in a Perl/CGI file. It places and looks right, but won't animate. I've stripped the CGI module down to an HTML skeleton, the CSS, and the...

animations don't work in any browser