Anyone else seeing this? Page load failures, sudden connectivity drops? UTM9

I'm running the latest build of UTM 9 home and have started to notice some strange behavior.  It happens mostly to wireless clients on my network, hard wired devices don't seem to experience the issue.  So think mobile devices, iphones and iPads. 

What will happen is that as I'm browsing a web page in the mobile browser, the pages suddenly stop loading.  I can't get anywhere, refreshes don't work and I have to drop off the wifi to LTE in order to load the page.  Usually going back on wifi will have things running again for a short time until it happens again.  Same thing running games and apps from mobile devices, you're in a network game and suddenly you get disconnected and it says it lost network connection in the game.  The device is still on wifi and you can ping the gateway but you can't get anywhere out to the internet.  

This is starting to drive me crazy because I can't see to find anything in the logs on the UTM that shows what the issue is.  I know its possible the issue might be with my wifi, but its an enterprise grade wifi system and has been working perfectly with no changes for several years.  I am upgrading the hardware for wireless again this week, so that will be interesting to see if it helps.  But I don't think its related to the wifi hardware.  

Any ideas from the UTM side of things where I could check basic configuration options or enable some kind of extra logging to troubleshoot?  

One observation I had so far is that when my connection drops I can manually enter the proxy settings in my wireless profile on the device and point it at the UTM on port 8080 and then it works again for a while.  But the same thing ultimately happens with those settings as well.  Its happening on multiple devices over wifi, mostly apple devices.  So maybe there is some sort of apple specific setting I can check?  

I'm using the transparent proxy on an internal trusted network.  Everything else is rock solid except for this strange sporadic connectivity issue.  I should also mention that laptops connected to the same wifi do not experience a problem like the mobile devices do.