(Possible wrong terminology!)
Downloaded files via API now have extra leading and trailing characters in file name: e.g. =?UTF-8?Q?data-sheet.xlsx?=. This is impacting internal rename_file() function and producing a warning: reason 'The filename, directory name, or volume label syntax is incorrect.
See https://github.com/allanvc/mRpostman/blob/master/R/decode-mime-header.R for example to remove.