Installed ethernet kext files because wasnt working, now I have another problem Help!!

My internet wasnt working so I installed what I think is the right kext for my motherboard and now I can open the Ethernet tab but it switches from "cable unplugged" to "Not Connected" every 5 secs look at this gif:https://imgur.com/pmtwZb5

Motherboard:MSI Pro Series Intel B250 LGA 1151 DDR4 USB 3.1 micro-ATX Motherboard (B250M PRO-VD)