Can not change SolaX Backup Discharge Min SOC

[jan-bee]

Hi,
I tried to set new "SolaX Backup Discharge Min SOC" by slider, but with no success.
entity: number.solax_backup_discharge_min_soc

Change of other values (like number.solax_export_control_user_limit or number.solax_selfuse_discharge_min_soc) working fine.
Inverter is running in Backup mode, because I want to prevent battery from discharging in some night times. In Self Use mode inverter go to "Idle" and it is not possible to wake it.

version 0.6.2 (same in 0.6.1)
HA 2022.9.5 (same in 2022.8.5)
SN: H34T (Solax G4 10K)

Do you have any hint?

Thank you.
Jan