My AC5300 is set to use one 5GZ band for wireless bridging and the other 5Ghz band for device connections. I addition the 2.4Ghz band also connects devices, I'm running Asus Merlin firmware version 380.68_4. I've been seeing tiis issue with several releases. I believe the last stable release that did not have an issue was 380.67_0. The symptoms are as follows: Devices connected to the AC5300 function without interruption but all of the bridged connections are lost. Devices connect on 5Ghz-1...
RT-AC5300 Loses bridged connections
RT-AC5300 Loses bridged connections