Issue with rxref #750

I am trying to use rxref between multiple deployments of stacker which are in same name space. I can see the new variable value in the change set but when deploying I am getting the following error:

stacker.exceptions.FailedVariableLookup: Couldn't resolve lookup in variable PublicSubnetId, lookup: ${Lookup<Literal<'rxref'> Literal<'subnet::oSubnetId'>>}: (<class 'botocore.exceptions.ClientError'>) An error occurred (ExpiredToken) when calling the DescribeStacks operation: The security token included in the request is expired

Has anyone seen this error?