Solis Cloud Inverters Daily Total CHANGES!

This is a question to anybody who has a Solis Inverter which uploads data via a dongle to the Solis Cloud Server
I’ve noticed that after a few days the daily total changes slightly
So, I have 3 Solis inverters which upload data to the Solis Cloud and at the end of each day I record the solar production from each of my systems into a spread sheet.
I recently noticed that if I then compare my recorded data with the Solis Cloud data a few days later the Solis Cloud data has reduced
For example
I record 2.7 kW production on 15/03/22
I check back on the Solis Cloud a few days later and its 2.5 kW
This is happening all the time with all 3 of my Solis systems
Can ANYONE explain why