SSH stopped working after GCP VM upgrade

[YD]

Google recommended (In the GCP dashboard) that I'll upgrade my compute engine, since my GCP instance CPU was working on 90%.
After doing that, following the dashboard instructions, I am not longer able to ssh to the compute engine VM.
When I try, the connection just hangs, I do not get any errors.

I can use the gcloud beta compute ssh command. which give the message "Unable to retrieve host keys from instance metadata."  but does connect.

the simple ssh stopped working, it just hangs out.
I created new ssh keys, but this did not help.

The issue is that I can no longer connect with pycharm and datagrip to the compute engine.

Any suggestion how this can be solved?

[Ahmad P - Cloud Platform Support]

Did you upgrade the CPU of your instance? 

Is any other user able to ssh to the instance using the same gcloud command?

You can run the ssh commands with this flag(--ssh-flag="-vvv") and provide additional details as to why the SSH operation is failing. 

Also you can debug the issue in the serial console.

[John F. Arroyave Gutiérrez]

Hi there.

Another thing that you can do is try to log-in using the serial console.

Serial console is also interactive and if you have a password establicshed for you root or another user you can login-in and check what's happening.

Best Regards.

[Christopher Allen]

Google recommended (In the GCP dashboard) that I'll upgrade my compute engine, since my GCP instance CPU was working on 90%.
After doing that, following the dashboard instructions, I am not longer able to ssh to the compute engine VM.
When I try, the connection just hangs, I do not get any errors.

A very obvious thing which you have probably checked already, but just in case:

You would have had to stop your instance before being able to edit it to change it to a larger one.  Did you remember to start it again after you edited it?