Code-Deploy is seccessful but then autoscale terminates all instances -

a new issue has started yesterday months of working correctly nothing being changed jenkins or aws settings

i have 5 machines in autoscale group git push triggering jenkins build , use jenkins aws codedeploy module push code-deploy. have deployment set oneatatime.

the issue starts when 5 successful , deployment marked successful. new deployment being triggered with:

initiated              autoscaling deployment config         codedeploydefault.allatonce minimum healthy hosts     0 of 1 instances 

for 5 individual deployments , 5 instances shutting down , terminated. managed grab 1 during net deployment , checked , nothing looks wrong. no errors. cdedeploy daemon running etc. after 5 individual deployments successful servers running fine.

what causing of sudden?

the new deployment has autoscaling creator caused instance scale event in asg. when deployment group created asg, , has been deployed, every time instance scaled up, deployment triggered sync new instance recent software other running instances. codedeploy has no idea why instance in asg got terminated, caused health check of asg etc.

thanks, binbin