CP 12400 in HA Cluster crash at same time after upgrade from R80.10 to R80.40 Take 120

[aboo008]

So, we have a severe issue that we are dealing with after an upgrade. We have a HA Cluster of 12400 appliances that were recently upgraded from R80.10 to R80.40 T118. We started seeing our FW's crash every few days randomly, after further analysis of the crash info and cpinfo it was suggested that to update to most recent Take 120. After that now we see crashes every few hours and it happens at the same time with both firewalls during this time we lose all connectivity to our internal apps and external sites. This has caused alot of issues. Current case open SR 6-0002952897 if anyone internal or R&D would like to take a stab at the case. Any help is appreciated. Thanks. 

Update: TAC recommended to disable GNAT according to the SK165153. This was implemented successfully now just waiting to see if the crash/reboot happens again. I wasn't able to get a clear understanding of how this SK would cause our FW's to reboot simultaneously.