Kds unauthorised request help

Hi, I followed the link below to install SambaPOS KDS on my tablet and set it up on SambaPOS.
https://kb.sambapos.com/en/8-9-how-to-configure-sambapos-kds/

However, it shows ‘Unauthorized request’ after I change ip address.

Last time I solved this problem by changing the server (the original post is shown below).

But it didn’t work this time. I checked all my settings and tried different PIN codes/passwords, but it is still happening. Can someone please help me? Thank you.

Try restarting message server. And make sure the ip is correct for message server in KDS admin.