Has this problem been reported on the Surf SOHO MK3 as well? I recently switched from an Asus AC66U and started having the issues reported here. Mostly running Apple products (a couple of MacBook Pros, iPhones, iPods, etc.). I have three VLANs configured - private, guest, and IoT. IoT devices include multiple Belkin Wemo switches and plugs, three nest cameras, and a Amazon Echo. Forcing the IoT devices to 2.4 GHz and the private network to 5.0 GHz helps the issue a lot but the WAN still drops out periodically. Additionally, forcing IoT to 2.4 GHz seems to be causing some of the Wemo devices to not connect (I believe I saw a similar problem reported on another thread).