Windows says that my link speed is 10/10 even tough it should be 100/100

Recently when I was about to install a game i noticed that my download speed only was 1MB/s, usually I get around 11-12MB/s because of my 100mbps internet. I did a speed test and it was like my internet suddenly is 10/10. I went through the network properties and as I thought it told me that my internet link speed is 10/10.

I live in a apartment and thought, well maybe the internet for the whole house is lowered. Well it isn't, another computer that is connected to the same router as mine (both with cable) has better internet, not the full 100/100 but in properties the link speed was 72/72. Since i had 100/100 before with the same cable i don't think the cable is the problem, I thought maybe something have happened in my computer, so I took the internet cable that goes into the router and plugged it into my computer, and suddenly I have 100/100, but as soon as I plug it trough my router it goes down to 10/10.

Now I have tried everything that I have found on the internet, I restarted the router several times, I switched the ports so i have the port that the other computer had, I logged into the routers web page but could find anything about my problem. it cant be a problem with my network adapter or anything else in my computer since it worked when I plugged in directly to the wall port.

Anyone have any suggestions on how to fix this?

The router is a D-link DIR-818LW