Hi!
Very strange behavior. Got a couple of LHG5 devices. Updated to the latest 6.42.4 router OS. Using Winbox to configure. After I choose QuickSet and select PTP Bridge (either AP, or CPE) mode, Winbox closes its window in ten seconds (approx) and router is not accessible anymore until configuration reset.
I researched the problem for a while. Evertything works fine (e.g. device even works as wireless router connected to my home AP via WiFI) until wlan1 interface is added to the bridge1. After that it goes in some dead state. Sometimes it continues to reply to pings, but neither ssh, nor browser can connect.