Inconsistency in MockServer configuration parameters

It appears that the config variables for Mockserver are sometimes used differently, e.g. sometimes they are used independently:

*** Keywords ***
Create Sessions
    Start Process  java  -jar  ${MOCK_SERVER_JAR}  -serverPort  ${callback_port}  alias=mockInstance
    Wait For Process  handle=mockInstance  timeout=5s  on_timeout=continue
    Create Mock Session  ${callback_uri}:${callback_port} 

SOL003 vnf inicator api variables:

${callback_uri}    http://localhost
${callback_port}    9091

while some other times:

Send Post Request for VNF Package Subscription
    Log    Trying to create a new subscription
    Set Headers    {"Accept": "${ACCEPT_JSON}"}
    Set Headers    {"Content-Type": "${CONTENT_TYPE_JSON}"}
    ${template}=    Get File    jsons/subscriptions.json
    ${body}=        Format String   ${template}     callback_uri=${callback_uri}    callback_endpoint=${callback_endpoint}      vnfPkgId=${vnfPkgId} **<- assumes port is included in the uri **
    Run Keyword If    ${AUTH_USAGE} == 1    Set Headers    {"Authorization": "${AUTHORIZATION}"}
    POST    ${apiRoot}/${apiName}/${apiMajorVersion}/subscriptions    ${body}
    ${output}=    Output    response
    Set Suite Variable    ${response}    ${output} 
    Run Keyword If    ${NFVO_CHECKS_NOTIF_ENDPOINT} == 1
    ...       Check Notification Endpoint
Create Sessions
    Pass Execution If    ${NFVO_CHECKS_NOTIF_ENDPOINT} == 0    MockServer not started as NFVO is not checking the notification endpoint
    Start Process  java  -jar  ${MOCK_SERVER_JAR}    -serverPort  ${callback_port}  alias=mockInstance
    Wait For Process  handle=mockInstance  timeout=5s  on_timeout=continue
    Create Mock Session  ${callback_uri} **<- assumes port is included in the uri**

My understanding would be that the correct version to be supported is the one with ${callback_uri}:${callback_port}.