In the PDF Viewer, we've utilized a list as the AnnotationToolbarItems component. Consequently, when the component is being destroyed, the list is also cleared. Hence, it's necessary to modify this list into parameter.
Current Code
<SfPdfViewer2>
PdfViewerToolbarSettings AnnotationToolbarItems="@AnnotationToolbarItems"> </PdfViewerToolbarSettings>
Expected Code
PdfViewerToolbarSettings> <AnnotationToolbarItems
HighlightTool = "True" </PdfViewerToolbarSettings>