Hello,
We use default wp_is_mobile function to show some things for the mobile and hide some desktop things for the mobile. But if you use cache plugin and Separate cache for the mobile devices option is not enabled you may face the mentioned issue. It means that the desktop version is cached for the mobile. In this case you don’t need to disable cache but enable a separate cache for the mobile devices.
So, enable cache plugin and provide us with WP Dashboard access to your site to check if you enabled the mentioned option in the cache plugin settings.
Regards