10 Feb
2022
10 Feb
'22
1:40 p.m.
I got a Chuwi for exactly this reason, to have a larger screen ebook reader which could handle pdfs, and seem to recall the same problem.
I think I fixed it by installing a different file manager.
The other thing worth trying might be to format the card from the tablet. I have a vague recollection of being prompted to do this at least once, but can't recall now if I did it or not.
Peter