The latest 1.26 ArmA3 release has created a number of issues with dedicated servers. I've seen this same mass de-sync behaviour on two seperate servers; hopefully the SimHQ server isn't effected by this...
UPDATE - Apparently BI Developers have said that after analysis, the problem appears to be isolated to the Dev branch only. We played on Saturday for two and a half hours without problems, so it seems to be true.
#4000043 - 08/24/1412:33 AMRe: De-Sync Issues with ArmA 1.26 Dedicated Servers
[Re: Gordo_Viper]