Have a RT-AC86U running 384.11 (will do 384.12 as soon as everything else is stabilized). With a Verizon DSL modem when we had one of the many power outages here in SW Florida that would eventually drain the UPS after power was restored everything would come back up without a problem. Moved to Comcast cable two days ago a using an ARRIS SBG6950AC2 Surfboard modem to replace the Verizon DSL modem. Now when power is applied to both the Arris and the AC86U at the same time I get the "dreaded" red LED. I didn't wait overnight (wife pressure) but I have gone more than 10 minutes in testing. The AC86U runs a VPN for the low IP range and straight out for the highest IPs that have devices that need location services streaming TV.