Not quite a bug. It happens because numeric's value when you are trying to set the range. Therefore, it's important to properly change the properties (in the right order). Attention - properties are executed top->bottom.
For example, when switching from prop2 to prop1, the attempt of setting minimum to 300 is unsuccessful because numeric value is 0 and LV will keep minimum to 0. To solve the problem, firs set maximum, then value followed by minimum. Anyway, pay attention that you'll have problems when switching back. Thus, manage the change with 2 different property nodes.
Hope this helps