Fixed menu with Firefox doesn't work ?

QuestionsCategory: Signature WP ThemeFixed menu with Firefox doesn't work ?
Roundcat asked 2 years ago

I can’t do work the fixed menu on Firefox otherwise it works on other browser like Chrome or Opera (I no test on Safari and Edge).
I see your comment and paste the code in assets/js/custom.js but it doesn’t work. Only the about section works.
How can I fix this problem ?
Thanks for your answer.