@Tomasm7 From what you describe, Satellite Deco believes twice a day that Sonos Speaker is not a LAN client (like a desktop PC) connected to Deco by Ethernet cable, but device that provides access to...

@AndrasN >http://tplinkdeco.net/ not working Have you tried http://tplinkdeco.net:30000 That works on some older versions of firmware Also, have you tried these both links, but with Main Deco IP...

@IgorBljahhin You may be able to get beta firmware for Deco M4, that can allow to disable Smart DHCP feature. See https://community.tp-link.com/en/home/forum/topic/155575?page=10 , posts #97 and #98....

@rozexir Using Main Deco with gigabit Ethernet ports, your Satellite Deco E4 which are wirelessly connected to Main Deco will get faster Internet speeds. Any Satellite Deco E4 that is wired will be...

@rozexir These are Deco E4 hardware specs: To get faster Internet speeds, you'll need Main Deco with gigabit Ethernet ports, such as: Deco S4, Deco M4, or Deco M5.

@greenawayr For what you described, usual suspect is newly introduced WiFi interference. Also, unlikely but possible, something is with Deco firmware upgrade. What is exact firmware version of your...