Search function in any PDF viewed from the files app on iPad specifically isnt working — GLITCHED

Every time I try the search function on my iPad, like a keyword in an e-book that I downloaded onto my iCloud drive, the function glitches in just 3 seconds and refreshes the whole PDF to bring me back to page 1. It has been going on similarly for both my old iPad Air 4 and now the new iPad Air 5! It is frustrating that I always have to use my macbook just to browse for the words or phrases in my PDF documents that are located on my iCloud Drive.