Under launcher settings → Tools / Cache → Shared Cache the Verify button used to verify downloaded files and purge extra currently only works on the files for the server that is currently selected in the launcher.
For one this behavior is not documented well and many would not know that you can do so for Singularity and Tranquility. Secondly, as someone who plays on Sisi frequently, it would be convenient if the button did so for all EVE files at once to save my time.