And you are sure you only have the one file selected? It would be shown in the filmstrip.
Assuming so, try saving metadata back to the files with Metadata> Save Metadata and then do a Metadata > Read Metadata. If the problem persists, then I'd suggest you try optimising the catalogue. If that doesn't work, force LR to create a backup upon exit (Catalog Settings) and let it run the integrity check. If it's still happening, this may be one where zapping the preferences might be the cure all.