@Tubabill 

If you’ve connected the ‘Move’ to your routers 5Ghz WiFi band, then perhaps switch it to the 2.4Ghz band instead - set the band to use a ‘fixed’ non-overlapping channel 1, 6 or 11 and if practicable, set the channel-width to 20MHz only.

The other thing to then try after that, if the issue continues, is to goto the Arc’s room settings in ‘Settings/System’ in the Sonos App and set the Arc’s ‘Group Audio Delay’ to a larger audio buffer size, either 113ms, or higher.
 

See if those things improve the grouped audio playback and prevents the audio dropouts on the Move.

Sonos speakers that are not part of a Home Theater bonded to an Arc or Beam (Gen1 or 2) will always have a 75ms delay when playing TV audio.  Neither can two Moves be used as surrounds. It is the Arc that is determining what signal is sent to speakers bonded to it.  @Ken_Griffiths suggestions may help but the Move will always sound out of sync with TV audio from the Arc. Music will always be in sync as it is being sent to all speakers simultaneously and not dependent upon the Arc. 

Thanks for the responses. Ken, you’re taking a foreign language to me. I the we are on 2.4Ghz. The problem isn’t a delay in sound, but the sound actually drops out. I guess I just can’t use the Move with TV is what you’re saying. It does work great for music. 

The Sonos ‘Move’ will/should work (without any dropouts whatsoever), but any Sonos HT in a ‘grouped room’ situation will likely mean you may encounter an echo/lip-sync issue, due to the buffering used in that type of scenario, particularly if the ‘Move’ (grouped room) is nearby, in the same physical room …that’s what @AjTrek1 was correctly referring to.

My own post was merely suggestions to hopefully help stop the audio from dropping out on the Move. If you do not understand the things suggested, then perhaps speak with family, friends, or colleagues who might be familiar with the things mentioned and able to help you make the adjustments to your network/system setup to (hopefully) improve the communication across the LAN, to at least stop the TV audio dropping out on the ‘grouped’ Move.

Hope that assists.

Thank you for all of your responses. I didn’t fix the issue, but I did move my Sonos 1 from the front of the house (dining room) into the living area. It now serves as a rear speaker for the TV and works fine. The Move is charging in the dining area and of course, can be moved anywhere. 

I’m a little surprised you are not encountering a noticeable echo in the ‘living area’ whilst the non-portable (Sonos 1) speaker is ‘grouped’ as a TV speaker, but glad to hear you are happy with your current chosen setup.

If you do encounter any echo problems at any stage, going forward, then you might want to consider adding another matching (Sonos 1) speaker to the room setup instead and ‘bond’ (not group) the pair to your Sonos HT, as that will/should work in perfect sync over the 5Ghz wireless connection between all the bonded devices.

Thanks for your thoughts and help, Ken.