connection drops randomly wired and wireless
For wireless there are many possible reasons, but wired is unusual as a problem.
You have “Log” in Winbox/webfig/CLI menu.
For more wireless info on the CAP add “Wireless” in “/System Logging topics=wireless”
You will get things in de Log like in this post: http://forum.mikrotik.com/t/feedback-capsman-tests-coming-from-unifi/154224/1
Wired connection is on the RB3011 only I assume.
For ethernet , never needed Log for analysing, but check error counter of the interfaces and check DHCP. If you do want logging add “topics=dhcp” and “topics=interface”, it might help (or not).
Just one possible remedy in this small setup is to modify all STP modes on all bridges from “RSTP” to “none”. RSTP will prevent network loops, but can stop all traffic for multiple seconds if a change in the network is detected.