Cannot delete because file doesn’t exist

There are three files on my iPad (two being the same file but one is continuously downloading) that have been there for two years. I have tried deleting them, restarting files, and my iPad has definitely reset since they showed up. Whenever I try clicking delete it gives me the message “The file _______ cannot be removed because it does not exist”. I never authorized the downloads in the first place and can’t get rid of them (they are slowing down the iPad). One of the files - Origin: Zip Archive. Data: 281.1MB.