Replying to my own post, I perhaps should have kept on hacking a little more before posting. The solution I've landed on is to use the 2.4GHz band with the laptop whilst limiting the radio channel width to 20MHz on this band via Omada Controller. This appears to have stabilised things which must mean that my HP Elitebook is a legacy device so far as the EAP225 is concerned (well it was built in 2012 tbf).

@JoeJoeJoe . I've experience Heartbeat missed when using EAP225 Outdoor. This is because i use 30m Cat5 Cable connected to EAP225. I think it's because the device it self. But after trying to connect mesh with my second EAP225 outdoor and do speed test, my root EAP225 outdoor always show heartbeat missed. This always happen after doing speed test.

 

After that i tried to change from 30m to 15m cable. Until now the device had no problem like before.

 

Maybe my experience has the same as you. Hope this will help.

Hi @waldi.top thanks for your reply. Whatever is going on here isn't cable length related, I'm using short patch cables and I'm testing indoors within 10ft of the EAP225. As an aside the thing that I mentioned in my 2nd comment that I thought was the solution didn't fix the problem, the instability and EAP225 crashes persisted. 

 

I continued testing and found that the EAP225 was horribly unstable with my HP Elitebook when registered and provisioned with Omada Controller and it has become a lot more stable since I've "forgotten" the device in there, stopped using Omada Controller and when I use and configure the EAP225 solely via it's direct HTTP interface.

 

I have no idea what's going on with it tbh, it feels bug ridden with my setup with this laptop and I've come close to giving up and sending it back but since it appears to have stabilized at the moment, I'm going to give it one last chance to remain stable and working before throwing the towel in.

You may have a newer laptop to do comparison test, so that you can figure out the issue is on your laptop or on EAP.