Good Morning Tom ,
So i had an issue with the classic cart of woo which in my website is in the menu .
It was showing one item inside even if i had none , that one was happening i guess cause of strong cache i have in my site .
It looks like it was not WP CACHE issue , but Redis . i have flushed the cache and works for now.
That was the reason i asked if is working with AJAX or PHP , but with REDIS does not make any sense.
I will have a look on that , for now anything else with REDIS seems ok but is first time i use it in GP site so i will check it more in time .