Interface auto negotiation failed

Hello,

I am very new to mikrotik world. Recently i have problem with mikrotik. Our mikrotik is can gv IP to users but the users cant surf the internet. All backbone is fine and DNS is up n running. If i have 10 users login, only 2-3 users can use surf and after awhile the packets/connection drop to 0 kbps and different users can surf, the rest cant. Any ideas?

2ndly when i compare two mikrotik side by side, i notice the interface LAN is not the same. One has auto negotiation at 100MBps and LINKed but other one auto negotiation failed. This mikrotik has above problem

Hi, two mikrotik have the same ROS version? Have You tried to upgrade ROS?