deepanshus Could it be temperature-related ? Do you charge at full power, or does your automation reduce the charging rate to be kind to the battery ?
Charging rate does tend to slow down as the system approaches 100%. There could also be some cell balancing going on - I don't know in detail how that works, but does tend to be quite slow.
When you charge from solar, you're presumably offering it power over many hours.
Or there seem to be different measures of SoC - in the app, when you go into the further information for the battery, it tends to show a lower value than the top-level bit of the app - possibly the true/raw capacity, including buffers /safety margins etc. Eg right now, app says my battery is 68%, but more information gives it as 67%. Perhaps your automation is accessing the raw SoC.