I'm suspecting some odd WiFi congestion or compatibility issue. 10MB is 100 megabit so that's above 802.11g's 54megabit. Let's hear about the client's WiFi and if you installed any hotspot shield or such.
Hello,
I installed my new wifi ac router (Asus RT-AC51U) in "router mode" then in "AP mode", but I have the same problem in the two cases : upload speed is good : 10 MB/s (like my fiber connexion), but the download speed is very bad : 1 or 2 MB/s (I should have 10 MB/s).
In fact it starts at 3 or 4 MB/s and quickly goes down to 1 MB/s.
I tested it with several tools (speedtest.net on my smartphone with many test servers and another Android app).
I have no problem with the download speed when wired, ie when I connect my computer on the RT-AC51U in router mode : download et upload speed are normal : 10 MB/s.
Also note that I updated the firmware of the RT-AC51U, I restarted all the devices several times, etc.
Please someone, do you have an idea ?

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