Why AWS EC2 Stop Working When a Github Action Start?

I want to deploy following application on a AWS EC2 Instanc-

1. Two Nextjs Application
2. One Nestjs Application
3. PostgreSQL Database

All the application is medium size application. For deploying this application-

I take AWS EC2 t2.2xlarge instance type which has 8vCPU and 32GB Memory. On this EC2 Instance, I deploy that two nextjs application and one nestjs application. I also install PostgreSQL for database on EC2. For automatic backing up, I am using cronjob and s3.

And I am using Github Self Hosted Actions for automatic deploy. I am facing that, when a github action is start to run, the whole EC2 instance stop working. All other sites not working, postgreSQL and nginx service getting stopped. Even In this moment, I can't connect to Terminal Both using SSH and Built In Terminal which we run on browser. I need to reboot the instance for re-working everything.

Note: It do not stop everytime. But If I push 5 times, it get failed 3 times, rest time it work fine.

I am not understanding, what is the problem.

1. Is my t2.2xlarge is not enough?
2. Or any configuration issues?

What instance type should I use?

Note: One my previous project I get same issue on t2.micro(1vCPU and 1GB Memory), and then I update it to t2.xlarge and then it does not the face that issues. On that project, I run two nextjs and one nestjs application.