There’s two possibilities here, for losing (not loosing) connection to the speakers. First and foremost is some sort of wifi interference , coming either from inside your network, or even outside of it. Worth reading the linked FAQ, certainly.

The second, more rare possibility is a network issue, wired or WiFi, specifically a duplicate IP address issue, often brought on by routers losing track of where they are in the DHCP table when the Sonos soft reboot during a software update. Easily rectified by unplugging all Sonos devices from power, and while they are unplugged, rebooting the router. When the router comes back up, plug the Sonos devices back in. 

There’s actually a third possibility, where there’s something going on outside your home, from a DNS issue, to the originating server having streaming issues. Since you didn’t specify what stream you’re talking about, it’s harder to make any judgement. 

I do reboot often. Due to this. I have ~20 connected device in our home, including Google Home speakers, hub and fire detectors. Also Apple TV and Chromecast. ASUS mesh system.

The only units that I have problems with is the Sonos, hence the annoyance.

Try wiring one of your Sonos speakers directly to the router to run the system on SonosNet instead of wifi

https://support.sonos.com/s/article/3209?language=en_US

Thar I have to do sometimes to find lost products in the app. However, not a good permanent solution with how I like to have my speakers and router.

If wiring solves the issue, consider a Boost https://www.sonos.com/sv-se/shop/boost.html

I used to have a bridge, so have a discount available for boost. However, still think it should work properly without. A system flaw

As you reboot often, please look at my post here: Tips & Tricks - Resolving random issues impacting Sonos devices.. | Sonos Community

So I managed to find and IP binding settingen for my router in the LAN configuration. It did not help. In fact I have lost a Sonos unit in the system everyday now.

Something is seriously flawed with the Sonos system here

Did wiring a speaker help?

Mesh can sometimes, but not always,mess up Sonos.

Hard to say if it helps. Wiring is not a permanent solution for me, sonof course I can connect units via wiring or wifi for that matter. The annoyance is about that the system is not available when units randomly goes missing. Not a premium experience. I do not expect a supplier such as Sonos should require network technicians, wiring or neccessity to configure static ip addresses really

Hard to believe that Sonos system could not be compatible with a ASUS mesh system

Hard to believe that Asus is able to make a device that doesn’t work with standard internet protocols. And that they’ve tried and failed with multiple firmware updates to fix their issues. 

That is it. It has gone from bad to worse, the app keeps loosing the units each day now.

And I truly believe this to be a Sonos issue since the Chrome and Apple units do not at all have this behavior in the same network.