Why am I getting VpcId: expected type: String, found: JSONArray error with my CloudFormation Template?

I am using this exact logic all over the place in my cloud formation template but for some reason the VPC ID does not want to work.

Below is a snippet of where I am using the VPC import (where the error hits).

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    DevTG:
        Type: "AWS::ElasticLoadBalancingV2::TargetGroup"
        Condition: CreateDevResources
        Properties:
            HealthCheckIntervalSeconds: 30
            HealthCheckPath: "/api/healthcheck"
            Port: 80
            Protocol: "HTTP"
            HealthCheckPort: "traffic-port"
            HealthCheckProtocol: "HTTP"
            HealthCheckTimeoutSeconds: 5
            UnhealthyThresholdCount: 2
            TargetType: "ip"
            Matcher: 
                HttpCode: "200,302"
            HealthyThresholdCount: 5
            VpcId:  
              -  
                Fn::ImportValue: "Deploy1-VPC"

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Here is what I currently have for the export in the Deploy1 script.

Outputs:
    # VPC
    VPC:
        Value: !Ref EC2VPC
        Condition: CreateDevResources
        Export:
            Name: !Sub "${AWS::StackName}-VPC"

Finally this is what my output looks like inside of cloudformation. I cannot see any reason why this would result in a JSON object versus a string.

This is because you are passing VpcId as an array here:

            VpcId:  
              -  
                Fn::ImportValue: "Deploy1-VPC"

Instead you should do:

            VpcId:  
                Fn::ImportValue: "Deploy1-VPC"