Why all ecs logs are not showing in aws cloudwatch logs--> missing logs

I have a ecs cluster with a service containing two tasks. When users log in in the node js app the logs shows socket.io connected successfully. This happens when the service has only one task. The logs get missing when there are two tasks. Read somewhere that sticky sessions will solve this socket connection issue, but the problem was still there.

Assuming that there was an issue with the cluster, we created another cluster with all the same confg, but in that cluster, even one task had missing logs.

How to resolve this? Any guidance will be appreciated.

P.s. we have alb attached to the ecs and logs are shown in cloudwatch log group