My jenkins job used to work fine , but as a monthly ami refresh, means on aws ec2, on which jenkins is running, we do a ami refresh of that ec2 after 2 months.
after that, problem started.
Then we tried to roll back to older ami(though the recent ami was not avaiable) ,but still the issue was same.
So, it doesn't looks like an ami issue.
But our main concern is, we are not able to see the errors in jenkins pipeline, it will just stuck at one at  some docker test cases.

we though, its an memory or cpu issues, we checked that in slave node, using htop and free-m, all looked good.
Then we thought, it jdk mismacth issue between master and slave, even after matching those jdk version, its the same issue.
we are using ec2 plugin for managing aws ec2 nodes on the go in jenkins.
So, our main concern is , we are doing hit and try as we don't have error, So, mainly we want to know the error.
our jenkins inside ec2 is running on docker, when we do docker logs container id, then this logs visible, but no help, will attach the log file.

I checked my slave agent logs, it was all fine, I have no idea where to check things.

Jenkins version: 
REST API
Jenkins 2.330