Can't change existing CSS rules using Developer Tools with Samsung Smart TV

Every time I try to change existing CSS styles from the “Styles” panel, I can’t use my keyboard,
that is, I can click on some specific style rule but when I try to tap I’ve got nothing it’s just doesn’t work.
When I try to enter CSS file and type something in this specific file
I’ve got the following error: " Debugging connection was closed. Reason: WebSocket disconnected ".

I’m bulding web app application, my files don’t reside inside Tizen studio but rather on the server.

Could someone please assist me, how could I change CSS style in the real time for my web app?

i have this problem with my samsung smart.