Ethernet problems with Windows 10

[oldschool]

Hi people
I am having a weird problem with my PC for quite some time now. I can't download files using my browser and ethernet. Wi-Fi works fine. Torrents work fine. When I try to download a file, I download about 5%, then my speed drops to zero, and there is a download error (I have to pause download and resume it after a few moments and it's the same thing all over again). Same on all browsers I tried (Firefox, Chrome, Edge, IE). Pages load fine. I contacted my ISP, they gave me a new router (but same model as the old one). Everything works fine on my other PC running Windows 7 that is connected to the same router. I even changed my MOBO and tried an ethernet card, same thing. Updated and reinstalled drivers multiple times, nothing. So I think it might be windows related. My MOBO is ASRock 970 Pro3 R2.0 and I am using Win 10 Pro x64 that is up-to-date.
Any ideas? Thanks