Just about one week ago I bought TP-Link router Archer A7 for my updated internet service plan from ISP and ever since I installed it, the download speed on my computer became extremely slow...like 3 times as slow as it should be. However, my other client devices, iPhones and IPads, are working fine without any issues, which confuses me so much.
Before I installed Archer A7, my computer can get almost 300Mbps download speed. However, after I installed A7, only no more than 100Mbps download speed can be obtained by my computer using the same cable.
So, I decided to contact the technical support of my TP-Link router. After some troubleshooting and remote assistant provided by their seniors, they found that download speed was detected normally as 300Mbps via Speedtest App on my computer, which means the download speed from our TP-Link router is working fine actually. But only https://www.speedtest.net via web browser on my computer detected no more than 100Mbps download speed from my TP-Link router. Under this situation, they suspected that this issue might be related to some settings or software of my computer and let me have a check carefully. I realized that I had download Norton Security Software on my computer at the same time when I installed Archer A7, which may be the clue.
Then, we tried to disable Norton Security on my computer temporarily to test the download speed by https://www.speedtest.net, no change. Finally, uninstalling Norton Security on my computer completely improved the download speed on my computer. It became normal and I have 300Mbps download speed again using speedtest.net.
My experience taught me that Norton Security has an influence on the download speed test via a web browser on our computer. To help other people who have the same experience as me, you can uninstall the Norton Security program on your computer to have a comparison test. Then, you will know what my point is.
At last, many thanks to the excellent support provided by TP-Link technical support and they solved my problem with their best effects.