Yup. We've run into that repeatedly. The "we didn't notice anything on our side, please send more screenshots and logs" gets really old when working with "managed services".
Network packet losses/truncations, EKS control plane failures, cloudformation stacks getting stuck in really wierd states, inconsistent cloudformation implementations for new and existing services, ENI weirdness in containers...
Managed services just feel like they aren't - more and more every day. Amazon (or any other cloud) will never have the same investment in your availability and infrastructure as you will.