PAGES IOS File date changes when the file is viewed. How to lock it.

I update Pages for IOS whenever an update is available. In the past (before the last update) when i Simple’s viewed a file (open in pages to see it) no editing just open look and close the file date stayed the same. Some files still have the “EDIT” button when i open them and those are not having the same issue. All the older files and the current files when opened and then closed all get todays date which is causing me problems when looking for older documents. How can i make every document have the lock for editing unless i press that “edit” button when its opened? Is the edit button no longer a feature? Is there a setup for the software where i have choices to control the documents?

Thank you for any input.