On what input? If it’s the TV on the Sonos (?) soundbar, it could be as simple as  wifi interference between the soundbar and your router, before the signal gets passed on to your Sonos CONNECT:AMP. A line in is generally ‘denser’ than a normal music stream.

Or, it could be a duplicate IP address issue, cropping up when you’re playing both at the same time. Less likely, mind you, you’d probably be experiencing this ‘drop’ at all times, not just when they’re grouped. 

In addition to ​@Airgetlam comments…..

• When did the dropouts begin; to the best of your recollection?
• Have you made any changes to your network? 
• Have you updated the firmware on your router? 
• Perhaps your ISP pushed out an update assuming they own the equipment?

Soundbar is hardwired to the TV. The problem is with the kitchen, when grouping the Soundbar and kitchen speakers. I have a mesh Wi-Fi system and have tried turning off “mesh” features for each device and auto-AP selection. I’ve had various Wi-Fi systems over the years but just recently noticed all my Sonos were offline. Soundbar and Connect:Amp were factory reset to get them re-connected.

Edit: Forgot to add that I tried using Ethernet instead of Wi-Fi for the Amp, but still had cutouts.

Hardwired to the TV only covers the signal getting from the TV to the soundbar, and does not cover it getting to your router, to be passed on.  You’d need to Ethernet cable both Sonos devices to your router to test the possibility of bandwidth issues, not just the CONNECT:AMP.

It might be helpful to know specifics about your mesh network, too. Especially since you seem to have been making changes to it as well. 

Thank you for your response. I have a TP-Link Wi-Fi 6E mesh network with access points all around the house. All my access points are hardwired.

Is your mesh system one that….

• You purchased components individually ( e.g. my mesh consists of three (3) ASUS routers that I configured)
• You bought a pre-configured system that is basically “plug n play’ (e.g. Orbi or TP Link)
• Supplied by your ISP

General Mesh parameters:

• Only the main node (router) should have DHCP capability to assign IP Addresses
• Recommended to use a Tri-Band router so that the extra 5Ghz or 6Ghz can be used as the backhaul which wirelessly connects all nodes (a Wired backhaul via Ethernet is best; but not required)
• Turn off Band Steering (or whatever the manufacturer calls it) wherein the router selects upon which band a WiFi product should use
• Recommended that bands (2.4Ghz, 5Ghz and some with 6Ghz) not be separated via different SSID’s 
• Same password used for all bands
• Wire devices to satellite node only under extreme conditions

General Network parameters

• When changing routers or ISP’s clink the link for detailed Pro Tips:

• Wi-Fi security be either WPA3 or WPA2/WPA3 (the latter being the preferred)
• Airtime Fairness disabled; especially for Sonos
• Turn off Band Steering (or whatever the manufacturer calls it) wherein the router selects upon which band a WiFi product should use

If you feel confident that your network meets all the suggestions above then I suggest you run a diagnostic as outlined in this link within 10 minutes of the failure. Then call Sonos tech support. Do not post the reference ID in this forum/community. You may have extreme interference and/or a failing Connect:Amp

EDIT:

Drats….That ​@Airgetlam guy was typing too fast and reading my mind 

I hardwired the Playbar and it’s no longer cutting out. Seems to have been a Wi-Fi issue. Going to just use Ethernet. 
 

Thx for everyone’s help!