GCP app engine flexible cloud build timeout issue

Question

I am trying to set up a pipeline for my Node.js app. The server is hosted on google app engine flex env and I am using cloud build to create the CI/CD pipeline.

For some reason I am getting the following error from the cloud build logs:

I set up my pipeline based on what I read in GCP docs and I really don't know why it isn't working.

This is my app.yaml file:

and this is the content of my cloudbuild.yml file:

I tried to search for it on the internet and found some things related to timeout but just how to add them to cloudbuild.yml and for some reason when I add it it crashes.

Now, If I will remove the timeout it will enter to some endless loop in cloud build and I found out that adding the timeout solve this issue.

If I use the standard app engine (not flexible) then it works, but I must use the flex.