For some reason, the init in the javascript hides everything BUT the joint billing partner code 
[![picture of after init][1]][1]


VFP: 

           <apex:pageBlockSectionItem id="PPJPN">
                    <apex:outputLabel value="Joint Billing Partner Name" id="Property__Joint___Name_lbl" for="Property__Joint___Name"><font size="3px" color="red">*</font></apex:outputLabel>
                   <apex:inputField value="{!DealerProperty__c.jointBillingPartnerName__c}"    id="Property__Joint___Name"/>
                </apex:pageBlockSectionItem>
                <apex:pageBlockSectionItem id="PPJPC">
                    <apex:outputLabel value="Joint Billing Partner Code" id="Property__Joint___Code_lbl" for="Property__Joint___Code"><font size="3px" color="red">*</font></apex:outputLabel>
                    <apex:inputField value="{!DealerProperty__c.jointBillingPartnerCode__c}" id="Property__Joint___Code"/> 
                </apex:pageBlockSectionItem>



Javascript:


         if(propModelVal.includes("JOINT")){
            $("[id$=Property__Joint___Name]").show();
            $("[id$=Property__Joint___Code]").show();
            $("[id$=Property__Joint___Name_lbl]").show();
            $("[id$=Property__Joint___Code_lbl]").show();
        }else{
            $("[id$=Property__Joint___Name]").hide();
            $("[id$=Property__Joint___Code]").hide();
            $("[id$=Property__Joint___Name_lbl]").hide();
            $("[id$=Property__Joint___Code_lbl]").hide();
        }


  [1]: https://i.sstatic.net/5EDHJ.png

edit: it is a dependant picklist if that makes any difference