I know exactly what he is talking about if its as though the fiddle does not want to play the notes you choose on any string.

There are some cheap yet old violins with a rather square shape at the top that will produce these unwelcome sounds. Getting the best sound post adjustment possible is not a total cure but works most of the time.

If the notes are all true then a loose seam is likely.
Which seam? Tapping various areas followed by the sound of a click will tell you where it is.