A few possibilities.
The BMS takes values from the settings and the algorithm calculates SOC from that and from full cycles between the values.
The default settings are
not optimal by any means.
Cutting off @ 24.2 / 3.025 Volts per cell is a bit high actually, 21.6(2.700) - 22.4(2.800) is more appropriate. When the BMS cuts off, what are the cell voltages ?
Have you changed the settings from the Default Lifepo setup ?
If you have, capture the screens and post them for people to look at.
Also, have a look at this link to compare with.
INTRO: I have debated posting this for a while until I got everything tweaked in and working as best as possible. The End Result is Gobsmackingly Good ! I cannot speak for other SCC and such as each is different & unique in their own ways BUT this may likely be a Good Reference. Civility &...
diysolarforum.com
Hope it helps, Good Luck