Mobile cache hit desktop cache

Hi,

My website run on a O2Switch with LiteSpeed Entreprise server. They use a reverse proxy to add the LiteSpeed server.

I have a PHP snippet that’s use the “wp_is_mobile()” function on my website.
Unfortunatly this function doesn’t work anymore when i activate the LiteSpeed Cache.
I activated the Mobile Cache as you recommend on others topics.
But when the cache is generated on desktop, the mobile users will hit this one and not the mobile cache, i don’t understand why this doesn’t work ?

I can see on mobile :

x-lsadc-cache: hit

in the Google Inspector but the “wp_is_mobile()” function is not trigger.