Kube-dns intermittent cannot resolve host

Cluster information:

Kubernetes version: v1.21.12-gke.2200
Cloud being used: Public cloud
Installation method: gke
Host OS: Ubuntu

so recently we encounter issue with some of our services can’t resolve hostname that had been setted up before. Any of you guys have same experience? if yes can you share it with me what is the common cause or how to solve it?

P.s : the one thing we suspect as the root cause is the high load of the services, but we still digging up more

thank you so much everyone !