Virtuemart cart page is not cached

[peta.dol]

Hello,
i am testing a LiteSpeed cache plugin in Joomla with Virtuemart and i have noticed, that all pages are cached (in header i see x-litespeed-cache: hit). Only cart page is not and x-litespeed-cache: XY is missing. Is that purpose or not? and how could i define this behavior?

You can check it here:
https://test.testbob.tk/kosik x-litespeed-cache is not in header
https://test.testbob.tk x-litespeed-cache: hit is in header

 

[serpent_driver]

The cart page may not be cached. This applies to the complete checkout process.