Sortable,js performance is very slow

Hello everybody and thanks of looking into my issue.

To better describe the problem I have - I created this very short screen cast

I am using grid of cards as displayed in the screencast, and when I try to arrange them they are so slow and respond with lag.

If, however, I try to use sortable inside of each card performance is normal. I have no other js functions running besides sortable at the time of dragging and dropping. I also don’t have any hidden elements as I saw that as a solution for sortable slow performance in a lot of cases. I couldn’t find any relative example to solve this issue and I have attached short screen cast to better show my problem.

Cards are unordered list elements inside the main ul with class .exercises so I have this in main jquery page:

$('.exercises').sortable();

and to move things around inside the card (for testing)

$('.exercises li').sortable();

Do any of you have any suggestion how to sort this problem as it really get annoying and it has been couple of days with no positive results.

Let me know if you need me anything else to provide in case I forgot. Thanks in advance for your time and help.