Set up for parallel inverters updates the slave not the master

[Chris-93SAR]

I have two Solis S6-EH1P6K-L-PLUS Inverters connected in parallel to one battery. When I set up the Solis Modbus Integration, I used the Device Info in this screenshot to reference the master inverter

Which Solis Cloud confirms is the serial number of the Master Inverter

Unfortunately, when I try to update items such as the charging and discharging slots or Export Calibration Value it is the Slave inverter that is updated even though the integration is not (directly) aware of the serial number for this device.
I would be grateful for any advice, please