Hello, I think the issue is due to GCC (Google Cloud Composer) that needs to spin up an instance to be able to run dbt, therefore the 2 to 3 minutes wait time you see before getting the log out, if you want to improve the performance of your environment in GCP I suggest following this guide Optimize environment performance and costs | Cloud Composer | Google Cloud
Remember that in GCP there is always a tradeoff of cost and velocity, hope this helps.