@Turpentine  Please check your patch cords and cables, faulty cables are mostly the reason for this kind of behavior. 

@TP-Link_Deco Thank you for getting back to me. See my replies below.

TP-Link_Deco wrote

@Turpentine 

 

Hello, thanks for reporting the issue to the community.

 

May I know the model number of the modem as well as the model of the switches?

>>> It's a Technicolor TC4400

 

Are they unmanaged switches or smart switches?

>>> Unmanaged switches. The one I'm using right now is a TP-Link TL-SG108, but I've tried two others before.

Something else that is strange: if I only have one device connected to the switch (which defeats the purpose, but just as a test), then it's fine, I've never experienced a drop in connection. 

 

When the TV or PC stops working when connected to the switch, are they still getting valid IP address from the network?

>>> No, nothing, it's as if there was no connection at all.

 

When they stop connecting to the internet, how about the LEDs on the two Deco M5s, are they still solid green?

>>> They are both green. The wifi also works totally fine.

jthcomputers wrote

@Turpentine  Please check your patch cords and cables, faulty cables are mostly the reason for this kind of behavior. 

Thanks @jthcomputers. Infortunately, I've tried with many different cables but it still happens.