Which operating system are you running on the tablet?
Do you have an Office subscription or just some basic version of Office with limited functionality?
Yes, I have a subscription. Just updated the app in the Play store about an hour ago, but the issue persists.
UPDATE: I had to use my computer's full version of Word to check the autocorrect options and remove the auto capitalization of "i" -- which, incidentally, is still annoying because now it won't auto capitalize if I actually want "I"... I tried adding "i[space]"
into autocorrect instead, but it wouldn't accept it.