Yea, I honestly don’t know, I’ve never looked in to the TP-Link to see how they really work, but this is a common issue, and I feel at least 75% comfortable in providing the advice.
If you’re setting up SonosNet (which you are, by wiring one Sonos device to the base router), then you don’t want the system to have the ability to use both connections, either the SonosNet one, or the regular wifi signal. The potential (not always, but it can happen) is for the system to “waffle” between the two connection methods, potentially causing slight interruptions in the data stream as the Sonos switches between connection methods. Ideally, there’s enough buffer, but I’m a fan of not providing any opportunity for confusion.
There’s more data here, if you’re interested, in the wireless and wired systems FAQ.
If, however, this suggested fix doesn’t change anything, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.
There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.
When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.