VS 2019 Trouble with assigning the result of a function to a property

Hi, my issue is that I can't seem to be able to assign a function's return value to an instance of a Class of same type:


More info on the above:

-PTriangle.Vertices is a property that returns an array of PVector objects.
-The "MultiplyVector" Function of the matrix returns a PVector object.

I want to assign the object returned by the function to each object looped trough in the array but it tells me "Unnecessary assignment of a value to Vertex"
I thought of making it a sub and directly change the PVector but I rather keep it as a function, how should I proceed ?
Is it in the PVector Class that I need to add something to allow this ?

Thanks in advance for the help !