Leaf Temp Offset between 0-2 has no effect

Checklist

[ ] I updated the card to the latest version available
[ ] I cleared the cache of my browser

Describe the bug I am using a ambient temperature sensor and a Hygrometer, the value for the leaf temperature is not measured. So I put nothing into the field for the leaf temperature sensor. Setting the value of the leaf temperature offset to a value between 0 - 2 has no effect on the VPD value. When using values >2.0 it changes the VPD.

Version of the card Version: v1.5.0

To Reproduce This is the configuration I used:

type: custom:ha-vpd-chart
sensors:
  - humidity: sensor.t_h_sensor_humidity
    name: VPD Leaf
    temperature: sensor.t_h_sensor_temperature
vpd_phases:
  - upper: 0
    className: gray-danger-zone
    color: '#999999'
  - lower: 0
    upper: 0.4
    className: under-transpiration
    color: '#1a6c9c'
  - lower: 0.4
    upper: 0.8
    className: early-veg
    color: '#22ab9c'
  - lower: 0.8
    upper: 1.2
    className: late-veg
    color: '#9cc55b'
  - lower: 1.2
    upper: 1.6
    className: mid-late-flower
    color: '#e7c12b'
  - lower: 1.6
    className: danger-zone
    color: '#ce4234'
is_bar_view: false
max_temperature: 30
min_height: 200
enable_tooltip: true
air_text: Air
rh_text: RH
kpa_text: kPa
enable_axes: true
enable_ghostclick: true
enable_ghostmap: true
enable_triangle: true
enable_crosshair: true
enable_fahrenheit: false
enable_zoom: true
enable_show_always_informations: true
enable_legend: false
ghostmap_hours: 24
unit_temperature: °C
min_temperature: 15
min_humidity: 30
max_humidity: 70
leaf_temperature_offset: 0

Expected behavior VPD is rising when rising the leaf temperature offset value from 0 to 2.

Desktop (please complete the following information): Home Assistant OS Core 2024.5.5 Supervisor 2024.09.1 Operating System 13.1 Frontend 20240501.1

mentalilll / ha-vpd-chart

Leaf Temp Offset between 0-2 has no effect #19