ICX 7250 stack switches rebooting

[network_adminis]

I updated to 8090 UFI on my ICX 7250s in most of the stacks unit 1 stays up but units 2 and 3 show that the have restarted sometime recently. Found this because my AP report disconnected but the monitor still thinks the stack it still up.

Just a few examples
STACKID 1  system uptime is 48 day(s) 22 minute(s) 54 second(s)
STACKID 2  system uptime is 2 day(s) 5 hour(s) 22 minute(s) 36 second(s)
The system started at 19:24:38 Pacific Mon Jul 01 2019

STACKID 1  system uptime is 37 day(s) 8 hour(s) 1 minute(s) 28 second(s)
STACKID 2  system uptime is 12 hour(s) 36 minute(s) 56 second(s)
The system started at 11:22:29 Pacific Fri Jul 12 2019

STACKID 1  system uptime is 37 day(s) 4 hour(s) 51 minute(s) 34 second(s)
STACKID 2  system uptime is 6 hour(s) 16 minute(s) 52 second(s)
STACKID 3  system uptime is 6 hour(s) 16 minute(s) 51 second(s)

STACKID 1  system uptime is 37 day(s) 5 hour(s) 5 minute(s) 7 second(s)
STACKID 2  system uptime is 11 day(s) 15 hour(s) 42 minute(s) 16 second(s)
The system started at 13:51:51 Pacific Fri Jul 12 2019
 

[netwizz]

Good Morning.  Does it give the reason?  Also anything in the log?  i.e. show logging

Something like this?

STACKID 1  system uptime is 52 day(s) 7 hour(s) 37 minute(s) 11 second(s)
STACKID 2  system uptime is 52 day(s) 7 hour(s) 37 minute(s) 22 second(s)
The system started at 23:48:16 Eastern Fri Jun 28 2019

The system : started=warm start   reloaded=by "reload"
My stack unit ID = 1, bootup role = active

[network_adminis]

STACKID 1  system uptime is 48 day(s) 22 minute(s) 54 second(s)
STACKID 2  system uptime is 2 day(s) 5 hour(s) 22 minute(s) 36 second(s)
The system started at 19:24:38 Pacific Mon Jul 01 2019

The system : started=warm start   reloaded=by "reload"
My stack unit ID = 1, bootup role = active

STACKID 1  system uptime is 37 day(s) 8 hour(s) 1 minute(s) 28 second(s)
STACKID 2  system uptime is 12 hour(s) 36 minute(s) 56 second(s)
The system started at 11:22:29 Pacific Fri Jul 12 2019

The system : started=cold start
My stack unit ID = 1, bootup role = active

STACKID 1  system uptime is 37 day(s) 4 hour(s) 51 minute(s) 34 second(s)
STACKID 2  system uptime is 6 hour(s) 16 minute(s) 52 second(s)
STACKID 3  system uptime is 6 hour(s) 16 minute(s) 51 second(s)
The system started at 13:58:33 Pacific Fri Jul 12 2019

The system : started=cold start
My stack unit ID = 1, bootup role = active

[netwizz]

Anything that says cold start most likely lost power on one of the stack units.

Also do you have hitless failoer enabled?  If not, it is likely more stack members will reset in the event of an issue.

Did you do a "show logging" and also a "show chassis" to see if there is anything logged or wrong with the power supplies, etc. ???

[network_adminis]

Hitless failover enabled.
Nothing showing up in the logs either.
Waiting for another failure to diag the issue