@RecapsGallion I think you probably need to look at the switcher/cabling, the router is probably not faulty :-) connect one switch at a time and see when the problem starts, then remove one cable at...

@RecapsGallion What happens if you disconnect everything on the router except wan, connect a PC directly to the router and run a speed test.

@Heraclite Im not shure where you find it in stand alone, but in controller mode is under advanced on device itself

@Heraclite maybe it's the echo server, try changing it to 1.1.1.1 see what happens.

@Mayte0110 The fix for now is to downgrade to previus version if you cant wait for a fix

@JackShepard sounds like a plan :-) one of my kids has two of these with 5.1.0 firmware and omada controller 5.9 on linux and ER605v1 whit 1.3.0, never had a problem. but if you test it at home do...