i have no experience of mesh systems, but most (maybe all?) of them use spanning-tree as a means to minimise the risk of switching loops (and broadcast storms as a result of the loops).
Sonos players also use spanning tree for the same reason.
do you know whether your sonos setup is running on the in-built sonos wifi mesh, or whether you have it connected to your own wifi..?
Use 'About my Sonos System ...' and check that the Wireless Mode (WM) is zero for each device, i.e it shows: "WM:0".
If you are in SonosNet mode already, Sonos devices will be picking up their WiFi signal from other Sonos devices, not from your current wifi setup.
if you end up going down the mesh route, it might be worth doing some research on any reports of issues between your preferred mesh system and sonos.
Sorry, problems not solutions, but figured it was worth pointing out.
If you want to avoid the mesh, then any premium router from ASUS, TP-Link, ZyXel, Netgear etc. should be fine.. if you still find that it doesn't reach the entire property, i'd probably opt to add an access point somewhere by running an ethernet cable from the router to wherever the wifi is week and stick an AP on the end of the cable..