After some network probing and talking to TP-Link support, I found out what the issue was. My results were subsequently confirmed by the TP-Link engineers. The Deco M5 units are always using 1500...

Hi! I recently bought a Deco M5 to extend my wifi network. At first, I was using it with my existing router, using Access Point Mode, pretty much without problems but then I decided to switch it to...