Hi!

I've run into a problem where my newly purchased Samsung Galaxy S20 phone is limited to 30/30 mbps in terms of wireless speeds on an Archer A9 EU model. I have a gigabit connection (1000/300), and I get those speeds over ethernet just fine. My other devices (a Galaxy A8 phone, a Galaxy A3 phone, my TV, etc) get speeds way higher than this (250/250 on the regular), which is completely fine, I expect the radios in those devices to do those speeds. But my S20, which should reach the router's max potential, seems to be bottlenecked by something.

It's not a faulty phone, I have a friend whose Samsung Galaxy S10 behaves exactly the same on my network. Also, I've checked the connection on an old TP-Link Archer A2 (AC750) router and I got 250/300 on this very same S20, which is I believe the maximum that old router can provide.

The fault must be somewhere in the Archer A9. Now, I've factory reset it a couple times, changed all the wireless settings (security, encryption, channel width, the channel itself, MU-MIMO, airtime fairness, etc) and tried every possible combination of them, but the S20 stayed at an almost precise 30/30, like something is limiting it. Can you help me figuring this out? Seems to be some very specific incompatibility between the A9 and the Galaxy S lineup. Maybe a setting I don't know of, a bug, or something along those lines.

Any help is appreciated.

Thanks.

Update:

I've been away for the day, and since I've got home I'm getting a new kind of strange behavior on the S20. When I start a speed test the download speed jumps up to 350 mbps, then instantly starts to throttle down and finally settles at around 120-140 mbps. The upload speed stays around a constant ~270 mbps, which, considering my service is 300 up, sounds about right.

Update 2:

I haven't disconnected or changed anything, and now the 30/30 cap appeared again.