Internet Disconnects On Lan But Wifi Is Ok

I use Windows 10 pro 64 Bit.
For the past few months there is something strange happening.
I use a Xiaomi Mi Router, all of a sudden on my desktop I find my internet is disconnected, but i am connected on my smart phone (as the same Xiaomi Mi router is giving the Wifi also.
So the internet is there, so the problem might be either based on my computer or the Lan port. etc.
When I hibernate the PC and restart it (within a minute) the internet is working again or other way is to restart computer.
I am not able to understand this problem, can anyone help on this issue?