Violin Moves All Over the Sound Stage

My bet is your system is totally fine. (But some good advice from others.) Actually, hearing what you're hearing, means you system is actually playing VERY nicely. 

So, that stereo version (which is on Amazon Music) has the violin playing INVERTED, out of phase--in other words it plays the violin, all around you, coming from no distinct spot AND it plays the violin in phase. It is a re-mastering issue. 

Playing a mono version will stop the floating violin. 

It's an amazing piece. Beethoven's only violin concerto. 

Heifetz or Ray Chen.

@fuzztone 

Heifetz was the king, but his inherently fast pace did not bring out the poetry of this great work. Of course my opinion only.

It could be that the recording has two violin players on it but it could be a setup issue with phasing or speaker placement, the speakers too far apart from one another.

There certainly won't be two violinists in the Beethoven Concerto.
Nonsense like that may turn up in today's gimmick-ridden world but not in this classic performance from 1959.