Please do post publish the HMI and slave versions, it will be most helpful. Also, does your source actually have the firmware? Multiple calls to Sunsynk, and each time they tell me different versions are latest and greatest for my 16 kW, but your list seems newer. My pant reports M 9.0.2.7 / S 1.7.2.6 / C E.4.3.D (which come from MCU1-SG-Ver0000-E43D-CK.bin and MCU2_9027US_NC_NR16K59V.bin)