If you try another plug will that go in fully?

Tried a few plugs. When I look down the port, it looks like there’s a small metal object which is not present in any of the other ports.

It must be a manufacturing error, I’ll give them a call tomorrow.

There is a mechanical switch which detects plug insertion in order to enable Line-In. It’s conceivable that it’s become misaligned. 

Sounds plausible. I won’t fiddle in case it voids any warranty :)

Spoke to Sonos today and they are kindly replacing the device. You were correct @ratty 

Took delivery of a Port earlier today to replace a Connect, and mine has the exact same issue’s. On phone now, hoping for a replacement. 

Not very impressed with it to be honest, the Connect has lasted years and never had any issues, currently they keep asking me to check things on my record player, but that works perfectly well with the Connect so it has to be an issue with the Port.
 

Fingers crossed they sort it anyway, expensive upgrade to not work

Yep. I’m in the same boat.

I just received a Port to update my ~7 year old Connect and I am having the same issue. The Line-in shows as Disconnected using the cable that was shipped with the device. Now that I look directly at it from the top, I can see that the left/white RCA is not seated as far as the red one is. I tried wiggling it around and pushing a bit harder, no dice. Faulty product.

...and now I’m suddenly bummed that I just bricked my old Connect. The new Amps feel like an upgrade, the Port does not.

After inspecting this a bit more. This is due to a bad RCA jack design.

In each of the RCA jacks there is a thin piece of metal that runs parallel to the male RCA plug’s pin. It is designed to rest on the plug’s pin with a bit of tension. In our case, the metal in one of my jacks must’ve been bent too far downward so when we plugged our RCA jacks in, it bent the piece of metal the wrong way and crushed it in the bottom of the jack.

Even with Sonos replacing device, with this design, it could take just one slightly misaligned plug-in to render your $450+ device useless.

Be very gentle and deliberate when plugging your RCA cables in with this new generation of devices (that sounds so ridiculous, lol).

I hope they fix it.

This is not good because not everyone uses line-in right away. Some folks might go a long time not using the input and then later when they have a need for it find that it doesn’t work (and probably never did). Sonos should send a warning to all Port owners to test the line-in while their unit is still under warranty.