Over the last month or so I have got problems with instant drop-outs after 4-5 seconds when playing my hi-res music. This happens when using ROON and also when playing direct from the KEF Connect app. The KEF speakers are connected to each other with the ethernet cable and wireless connection to my network. My main system using ROON with Auralic Aries G2 player (and Kii Three speakers) have no problems at all playing all my hi-res music ( 88/96/192kHz +DSD). The Auralic Aries G2 are also wireless connected and are placed only 30 cm / 12 inch from the main/master KEF LS50 W II speaker so the wireless signal here should be good and the same for both. The speed on my network are stable on 75 Mbps.
I have experienced a similar problem: dropouts on the KEF but rock solid streaming on my Bluesound Node 2i and Pulse Flex 2i. This is the case even when the KEF is nearer to the mesh wi-fi node than the Bluesounds.
I have consulted KEF Technical Support twice and the response has been mainly instruction in the factors that affect wi-fi connectivity such as distance from the router or node, contention for bandwidth, whether you are connecting to 5GHz or 2.4GHz, etc. On the first occasion I was advised to delete the existing Connect app and install the latest v1.8.1. This I did and, while it didn’t resolve the issue, it does provide a useful Speaker Connection Test and a link to written advice on improving connectivity.
This very day, I spent several hours exploring the issues by trial and error and trying to establish the conditions under which the KEF LS50 WII will consistently connect wirelessly without dropouts and came to the conclusion that there are none. Even less so if you want to group a number of Roon-ready devices for multi-room playing which, of course, increases the contention for bandwidth. In my view the only sure fire solution is to provide the primary speaker with an Ethernet cable connection to your network. However I have found that this doesn’t have to be all the way back to the router. If you have a mesh system whereby the wi-fi signal is distributed intelligently through a series of wirelessly connected nodes you only need to connect the LS50 WII to the nearest node, assuming it has a LAN port.
When you consider the basis on which these speakers are marketed - hi res music, minimal cabling and high aesthetics, etc., it is disappointing to find a marked lack of robustness in their wireless connectivity such that you have to resort to more cabling and (as in my case) having to invest in an additional mesh node.