Activity, when modified is not accurate

owncloud 10.0.10

current Activity app

File modified information isn’t always correct.
There are some documents that look right, but some are definitely wrong. One pdf document, which was created months ago is showing modified seconds ago (seems to be list how long ago I logged on). When I download the documents, the date modified does match what is being shown in owncloud. Is there something that could be “modifying” the documents as part of some process or function?

Any help is greatly appreciated.