Rerender is not triggered within <apex:repeat> block

Question

I have a scenario where there are repeating Tabs. Within each tab, there are multiple drop-down lists (say DL1, DL2, DL3). DL2 is dynamically generated based on the value selected from DL1. And DL3 is dynamically generated based on the value from DL2. I implemented something similar as:

<apex:repeat id="repeat1" value="{!reps}" var="rep">
.
.
.
    <div id="div1-{!rep.id}">
        <apex:outputPanel id="DL1" >
            <apex:selectList value="{!selectedVal1}" size="1" id="SL1">
                <apex:selectOptions value="{!list1}" />                                                                                                                                
                    <apex:actionSupport event="onchange" rerender="DL2"/>                                         
            </apex:selectList>
        </apex:outputPanel>
    </div> 
    <div id="div2-{!rep.id}">
        <apex:outputPanel id="DL2" >
            <apex:selectList value="{!selectedVal2}" size="1" id="SL2">
                <apex:selectOptions value="{!list2}" />                                                                                                                                
                    <apex:actionSupport event="onchange" rerender="DL3"/>                                         
            </apex:selectList>
        </apex:outputPanel>
    </div>          
    <div id="div3-{!rep.id}">
        <apex:outputPanel id="DL3" >
            <apex:selectList value="{!selectedVal3}" size="1" id="SL3">
                <apex:selectOptions value="{!list3}" />                                                          
            </apex:selectList>
        </apex:outputPanel>
    </div>
.
.
.
</apex:repeat>

Issue: Rerender is not getting triggered on DL1. This seems to be because this is within the "repeat" because I have a similar feature implemented outside repeat and it works without any issues.

I tried the following options after browsing several links but still no luck

1. Set Outputpanel layout attribute to "none"

2. Tried to assign a dymanic id to Outputpanel. But VisualForce throws error " Literal value is required for attribute id in <apex:outputPanel>"

3. Modified code to rerender as rerender="repeat1:DL2"

4. Modified code to rerender as rerender = "{!$Component.DL2}

I am a newbie to SalesForce. Any help would be greatly appreciated!

Thank you!

Answer 1

Thank you for the help! The issue is fixed now after the below changes

1. Unknowingly I had the selectList value declared as both the list and the getter by mistake which prevented the onchange event to trigger. I removed those duplicates.
2. As the selectList value was static, the value was not set correctly. Modified it to store in a Map so that it can be dynamic for each repeat