When a solute is added to a solution it remains homogeneous because the solute dissolves and is evenly distributed among the solution.
For a solution to not be homogeneous it must have distinguishable parts that are different from the base of the solution. As an example, a salad would not be a homogeneous solution because you can distinguish the different parts just by looking at it.
An example of a homogeneous solution would be salt water because the salt completely dissolves into the water.
Hope this helps and have a nice day! :)