Lab 11.2 nginx-ingress-controller fails Readiness/Liveness probe after Linkerd inject

Every thing works fine until line 11. After linkerd inject, the controller container will fail inside of the pod which now has a new linkerd-peoxy container. Here are the results of describe pod:

 Warning  Unhealthy  1s (x2 over 11s)  kubelet            Readiness probe failed: HTTP probe failed with statuscode: 502
  Warning  Unhealthy  1s (x2 over 11s)  kubelet            Liveness probe failed: HTTP probe failed with statuscode: 502
  Warning  FailedPreStopHook  5m14s                  kubelet            Exec lifecycle hook ([/wait-shutdown]) for Container "controller" in Pod "myingress-ingress-nginx-controller-wftqp_default(e7df6293-4dbc-4cf8-8948-7cb161efda48)" failed - error: command '/wait-shutdown' exited with 137: , message: ""

The container enters CrashLoopBackOff and stays that way. This causes all the requests sent through the dashboard in step 12 to fail.

I have been struggling to figure out why, but I can't and I need your help.

My ingress-nginx is version 4.0.6 (I had to add ingress class to make the rule work).
My environment is GCP with two machines of n1-standard-2 (2 vCPUs, 7.5 GB memory), as suggested by the class.