After upgrading to Sitecore 9.2 and SXA 1.9, why is Personalization is failing on all renderings?

Question

After upgrading to Sitecore to 9.2 and SXA 1.9, personalisation on all renderings started to fail.

When the page loads for the first time, the item is rendered as expected, however, any subsequent page refreshes result in rendering item not being displayed.

public class MyComponentRepository : ModelRepository, IMyComponentRepository
{
    public override IRenderingModelBase GetModel()
    {
        MyComponentModel model = new MyComponentModel();
        FillBaseProperties(model);
        var checkDataSource = model.DataSourceItem;
        return model;
    }
}

I found var checkDataSource = model.DataSourceItem; was returning null on page refresh.

Answer 1

So, I inspected FillBaseProperties(model) in the Sitecore.XA.Foundation.MVC dll:

IRenderingModelBase renderingModelBase = (IRenderingModelBase)model;
renderingModelBase.Item = this.Rendering.Item;
renderingModelBase.PageItem = this.PageContext.Current;
renderingModelBase.Rendering = this.Rendering;
renderingModelBase.DataSourceItem = this.Rendering.DataSourceItem;

I found that on first load, the this.Rendering.DataSourceItem was populated with Sitecore Item GUID, however, on subsequent page refreshes, it was null. The this.Rendering.DataSource was always populated with "local:/Data/myDataItem".

Sitecore Support have confirmed that this is a bug (reference number 362374) and have suggested the following fix which resolved our issue:

Go to App_Config\Modules\SXA\Foundation\Sitecore.XA.Foundation.XConnectIntegration.config and change the following entry:

<mvc.customizeRendering>
 <processor patch:after="*[@type='Sitecore.ContentTesting.Mvc.Pipelines.Response.CustomizeRendering.SelectVariation, Sitecore.ContentTesting.Mvc']" type="Sitecore.XA.Foundation.LocalDatasources.Pipelines.CustomizeRendering.ResolveRenderingDatasource, Sitecore.XA.Foundation.XConnect.Integration" resolve="true" />
</mvc.customizeRendering>

To the following one:

 <mvc.customizeRendering>
   <processor patch:after="*[@type='Sitecore.Mvc.Analytics.Pipelines.Response.CustomizeRendering.Personalize, Sitecore.Mvc.Analytics']" type="Sitecore.XA.Foundation.LocalDatasources.Pipelines.CustomizeRendering.ResolveRenderingDatasource, Sitecore.XA.Foundation.XConnect.Integration" resolve="true" />
 </mvc.customizeRendering>

Also make sure that your web.config has the following app setting with the value 'sxaxconnect':

    <add key="sxaxm:define" value="sxaxconnect" />