Unexpected Battery percentage dropping

My battery system is 13.6 kWh.
At 7:31:49 today my battery percentage was reported as 61% but at 7:35:54 it registered 50% - that's about 1.5 kWh in 4 minutes but battery power at that time is shown as 141W !!
by 9:32:33 PV input had increased the percentage to 61% but 3 minutes later at 9:35:46 it had dropped to 30% - over 4kWh in 3 minutes and again the battery power at that time is shown as -1340W (charging from PV)
The "Discharge Today" figure is 1.9 kWh,
The "Generation Today" figure shows 6.70 kWh HOWEVER, the "Energy Graph" box on the left shows "Today's Generation" as 3.50 kWh.

Anyone any ideas about these sudden drops and the differences in the Generation figures ?

GeoffEvans I could be that you need a recalibration is the SOC is changing by that much. My understanding is that the BMS will lose track of the charge over time especially if the battery has not been cycled recently (i.e. going from full to empty). There are other posts on here where you can find more information on recalibrating the battery

Welcome to the world of GivMaths! Its quite normal for there to be a difference between the different parts of the portal. For instance at the moment the Legacy Graph box shows my gen as 19.8, the new Graph box shows 17.2 and the yellow Generation Today shows 22. I suspect they are all taking timed views of the data at different times and the new & legacy graphs are then applying GivMaths random number generator treatment to it.

With regards the % swings, thats pretty wild up and down but its a known long running problem with PV charging and systems that dont go to full and empty very often. The BMS 10 thread has a LOT about it
https://community.givenergy.cloud/d/4748-all-in-one-bms-release-10/581