I'd also like to add, since the recent Deco S4 update, my network is acting strange. 

My S4 has a weak signal source from the main router, and in the bedroom, with a Deco S4 placed right outside the door, devices connect to my M5 downstairs instead. I don't think it did this before. 

@TP-Link Hello there, my apologies for the late response. I have been testing this further and have some more information. Are you still available to help with this issue? Thanks

I would like to confirm that I did swap the two Deco S4's and can confirm I have the same problem. I have noticed that it seems to affect both devices. For instance, if I set something to download on my laptop, while it is wirelessly connected to the S4 that is located in the bedroom, then network speeds on my PS5 will tumble. And vice versa. If the PS5 is downloading, then the laptop internet speeds will tumble. 

It seems as though it can only handle one device downloading something, which seems a bit bizarre for a mesh system that is designed to hold up to 100 devices

I can provide more information if needed. My other Decos do not behave like this as far as I can tell. This Deco is also the only one that isn't connected to the main router Deco, but uses a different signal source. 

@TP-Link Yes, that's correct. If one device starts downloading something, the speeds on other devices connected to that Deco go down massively. 

Do you have an example of the network topology so that I can ensure I send you the right thing?

When the speed drops, I don't need to reboot to get them back, I just have to pause the download. It seems to work fine when nothing is downloading.

Also if it's not too much trouble, can I just ask why you would need the email address associated with the account?

Thanks

@TP-Link Hey there, thanks for reaching out. Apologies for the delay, I have received your email and responded