The unit of sensor.grocy_stock is changing, got multiple {None, 'Product(s)'}

[StefanoGiu]

Describe the bug
Error in the log

Expected behavior
Fix the error

To Reproduce
Every HA startup I see the below error

General information to help debugging:

What is your installed versions of Home Assistant, Grocy and this integration? HA 2024.4.0 and lastest grocy

How do you have Grocy installed? Add-on or external? custom-component

Additional context
2024-04-11 14:01:29.103 WARNING (Recorder) [homeassistant.components.sensor.recorder] The unit of sensor.grocy_stock is changing, got multiple {None, 'Product(s)'}, generation of long term statistics will be suppressed unless the unit is stable and matches the unit of already compiled statistics (Product(s)). Go to https://my.home-assistant.io/redirect/developer_statistics to fix this