I'm trying to pass value for <apex:inputField> to wrapper class, but it doesn't work. The form does show the data from wrapper class which I think the get() is working but not the set(). I have turned on debug log and none of the changes (on the input field) has been passed on to the controller. Could someone point out where the problem is?

VF page:

<apex:pageBlockSection title="Meal Options" columns="1">
                <!-- Choose which product family-->
                <apex:actionRegion >
                    <apex:selectList value="{!SelectedProdFamily}" multiselect="false" size="1">
                        <apex:actionSupport event="onchange" action="{!applyFilter}" reRender="myProdList"/>
                        <apex:selectOptions value="{!ProdFamily}" > 
                            Product Family:  
                        </apex:selectOptions>
                    </apex:selectList>
                </apex:actionRegion>
                
                <!-- Product options table with pagination -->
                <apex:pageBlock >
                    <!--Table of available products and quantity -->
                    <apex:pageBlockTable value="{!selectProds}" var="sp" align="center" id="myProdList">
                         <!-- below is the input field which doesn't pass on the value to the binding wrapper class-->
                        <apex:column headerValue="Quantity">
                            <apex:inputField value="{!sp.mItem.Quantity__c}" required="true"/>
                        </apex:column>
                        <apex:column value="{!sp.pd.name}"/>
                        <apex:column value="{!sp.pd.Family}"/>
                        <apex:column value="{!sp.pd.Grams_of_Protein__c}"/>
                        <apex:column value="{!sp.pd.Grams_of_Fat__c}"/>
                        <apex:column value="{!sp.pd.Grams_of_Carbohydrates__c}"/>
                        <apex:column value="{!sp.pd.Quantity_Remaining__c}" />
                    </apex:pageBlockTable>
                    <!-- Button panel for product form-->
                    <apex:pageBlockButtons location="bottom">
                        <apex:outputPanel id="myButtons">
                            <apex:commandButton action="{!First}" title="First" value="|<First" disabled="{!disablePrevious}" reRender="myProdList,myButtons"/>
                            <apex:commandButton action="{!Previous}" title="Previous" value="Previous" disabled="{!disablePrevious}" reRender="myProdList,myButtons"/>
                            Page {!pageNumber} of {!totalPages}
                            <apex:commandButton action="{!Next}" title="Next" value="Next" disabled="{!disableNext}" reRender="myProdList,myButtons"/>
                            <apex:commandButton action="{!Last}" title="Last" value="Last>|" disabled="{!disableNext}" reRender="myProdList,myButtons"/>
                        </apex:outputPanel>
                    </apex:pageBlockButtons>
                </apex:pageBlock>
            </apex:pageBlockSection>

Controller:

public PageReference applyFilter(){
        
        Meal_Item__c temp = new Meal_Item__c();
        if(MealItems.size()>0){
            For(ProductOptionData p : SelectProds){
                    system.debug('test'+p.pd.id);
                    system.debug('test'+p.mItem.Quantity__c);
            }
        }
        SelectProds = SelectProds();
        return null;
    }

//Wrapper class
    Public class productOptionData{
        Public Product2 pd{get;set;}
        Public Meal_Item__c mItem{get;set;}
        
        public productOptionData(Product2 pd, Meal_Item__c mItem){
            this.pd = pd;
            this.mItem = mItem;
        }
    }