Stalled Files App (iPad Pro)

Has anyone experienced an iPad Pro (12.9) (4th Generation) being taken over by a PDF file downloaded to ‘My Device?’ I’m running 14.3. and retrieved the file from a university online canvas. The PDF has commandeered my ‘Files App’ with a blank white screen and the PDF file name as header. It does not respond to input, and has rendered my ‘Files App’ inaccessible. ‘Files App’ by iPhone 12 Pro, remains. Any suggestion toward a remedy is greatly appreciated. Thank you.