Moving Folders Between Sharepoint Sites ignores Office 2003 and earlier files

We have Office 365, and occasionally have to move files and folders from one site to another as customer and other business adjustments happen.

When we use the MOVE feature in SharePoint online in the browser, the Office 2003 and earlier files get left behind. .XLS, .DOC, .PPT. We've never had a problem with Office 2007 and later files (.XLSX, .PPTX, .DOCX) and non-office files (PDF, TXT, etc) getting left behind.

Has anyone else seen this, and have a suggestion? It makes for a complete mess trying to get the old files to the new site and integrate into the folder structure.

Browser doesn't seem to matter. We've replicated this in Legacy Edge, Chromium Edge, Chrome, and even tried IE.