What i would suggest is that you set up a local syslog server and enable the syslog feature on ZD to start pushing all the logs to your server so that
you can take a look. goto --> ZDGUI --> configure --> system-> syslog
Also enable diagnostic for client so that you see what you are looking for.
goto --> ZDGUI --> Admin tab --> diagnostics --> debug logs --> only enable for 802.11
If you are one of those who are always in the field then i suggest you go for online/cloud syslog server like - https://papertrailapp.com/
again same way point your ZD to papertrailapp.com so that you can see syslog on the move on their website
try out papertrailapp.com as they have free account too and easy to config. You see logs literally realtime.
hope this help.