Trust Policy Principal gets converted to random string

I have setup a Trust Policy in my Identity Pool auth role. The trust policy allows a lambda role to assume the role. Everything works fine, but sometimes after doing Amplify push, the Principal in trust policy in the auth role gets converted to this random string and looks like this. It is supposed to be arn of the lambda role.

{ "Sid": "Statement1", "Effect": "Allow", "Principal": { "AWS": "AROAVK34QRIAIG3JRODO3" }, "Action": "sts:AssumeRole" }