Thanks for reporting the issue! The feature is actually working, but its behaviour is not very clear. When you tick RANGE AXIS CUSTOM MIN/MAX, you also have to change the Min and Max values RANGE AXIS MAXIMUM and RANGE AXIS MINIMUM from the above input boxes. When you tick the box without changing the above values, the default min and max are taken, which are 0 and 1, and since the mapped data values are quite different, it looks like nothing happens.

The feature should be Improved for more clarity in a next version of Vanted by:

1. Synchronising the starting attribute min and max with chart min and max, so that when the custom axis checkbox is ticked, the chart remains unchanged, until new min and max attribute values are set.
2. Adding a tooltip to custom axis checkbox hinting the need to change the min and max attribute values.