Istio Sidecars Failing to Connect to Pilot

When first deploy Istio, everything worked as expected, however after a short while on the cluster, any pods that are terminated, fail to connect to pilot.

Running Istio version 1.1.6,

Has anyone had this issue before?

Restarting Pilot fixes the problem, until a short while after it starts again.

Thank You.

Maybe you can check both the sidecar and pilot logs