Procedure to replicate1. Open the URL: https://ej2.syncfusion.com/demos/#/material/pdfviewer/default.html in iPhone X, safari browser.2. When the page is loaded, and the first page of pdf is displayed in the pdf viewer, touch the middle of the page document and slide finger up.
3. The pdf will not scroll up and we will not be able to view the other pages of pdf.
4. If we touch on the page number bubble in the bottom of and slide up, the pdf will scroll.
PDF document - The same pdf viewer int the Syncfusion demo, mentioned.
Mobile configuration - iPhone XR, Software version 12.3