Missing or Corrupted DispForm.aspx and EditForm.aspx Files

During the migrations from the on premise to SharePoint online (modern team site) with Sharegate, we noticed versioning and the ability to edit document properties corrupted or broken due to missing DispForm.aspx and EditForm.aspx files.  We tried migrating a fresh copy from SharePoint online for this document library; even tried creating a new one or modifiying exisitng ones... all we get is "access denied".  Because the scripting feature is disabled and the files are locked down, any suggestions in restoring these files to the original state other than recreating the documents library or the site collection?

Thanks,

Chris

Tips:  When migrating content with the use of "Copying Site Objects" option, be sure to uncheck "customized forms and views" before migrating on premise site lists/libraries to SharePoint online (modern site).