Dear Support team
Thank you for your help and guiding me through different possibilities.
In fact, it was the endpoints which were consuming the resources.
I had 11 missing compute cores:
My colleague and I had created 3 one-core machines and one 4-core machine with 2 instances which add up to 11 cores. (Though the deployment failed but it consumed and dedicated the resource.
One I shut them down, the resource got free.
Note for fellow developers: At first, I was using real-time endpoint(quick) and then I realized it assign number of instances to more than 1 for load balancing. If you (like me) are in short of resources, do not use this option and go with real-time endpoint.
Thank you very much again.