Azure 64 Cores VM was throwing System OOM encountered

In Azure, we were trying to deploy istio1.1 in 64 core VM but it was throwing System OOM encountered error. Also the istio pilot, istio policy and istio telemetry pods were keep on restarting. No applications were deployed only istio was deployed. While running top query istio ingress gateway was using 230% compared to 80% target and didn’t notice any memory issues. After reducing to 32 core VM didn’t notice any issues with the same istio. Any suggestion?