Hi @B_97,
I agree with @Mloraditch here, Event Log will be helpful here. In addition to that, I would recommend reviewing the Wireless > Monitor > Health > Connection log page since it includes more detailed information about the failure and can provide you with the most likely root cause of the issue.
You can also use a new Assurance tab to view Client Impact in your wireless network to see if this is possibly more wide-spread issue.
Once you reviewed the Connection log and assurance tab, I would recommend to scope the issue and see if this is related to a specific client device/SSID/AP etc. Also see if you can reproduce it on-demand, or the issue is intermittent - this will be helpful information to understand the root cause.
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