Trusted Entities in the AWS IAM role

Question

I have a cross account role which gives some permissions to two lambda functions from another account. Recently I noticed my cross account role trusted entities keep getting modified (the lambda roles ARNs been removed from the trusted entities and I had to add them back). I'm not seeing any event in the cloudtrail related to this change. So I talked to the other account administrator and I figured they been removing and recreating those two lambdas sometimes. So I assume AWS IAM would remove the trusted entity ARN from my role if the entity doesn't exist anymore? Is this a correct assumption?

Answer 1

I have never seen an ARN be recreated like that. Seems like a bug in the service?