It’s related to your cache system. We use wp_is_mobile default function to show mobile version for the mobile devices. But your cache does not separate cache for the mobile devices and display cached mobile version for the desktop.
Do you use third-party cache plugin or some kind of the server cache? You need to contact either plugin author or hosting provider and ask to separate cache for the mobile devices to avoid mentioned issue.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.