That's why I never use Save, it keeps it often in series and the engine is cycling on - off every few minutes. Why when I have the option to manually control my SoC and keep it in Parallel by using Charge.
People see instant fuel consumption jumping a bit and the word "CHARGE" compared to"SAVE"
ending up with wrong conclusions.
BTW better use Charge in low to mid state of battery charge. Don't charge it to 89% SoC unless you have very long city driving ahead of you.
Do same cycles Charge on and off but from 10%-20% to 50% SoC.
The battery is accepting the charge easier when low. Although I saw some measurements posted from watchdog app that there is virtually no difference in accepting the charge even in high SoC state.