Hello Lenny,

Thank you for reaching out, and I am happy to help!
Can you please disable minify in the W3 Total Cache Performance>General settings, save all settings, and purge the cache, and see if the issue persists?
If the issue is gone, re-enable minify, and disable the settings in Performance>minify one by one (HTML minify, JS minify, CSS minify) and see which one might be causing the issue.
Make sure to save all settings and purge the cache after each option is disabled.
Thanks!