Battery not charging overnight

Have noticed that things have not been quite as expected, low battery in the morning. But have only now been able to check.

10th September all was fine
11th There is no data before 09:03:36 when the battery was 86%
Since then the battery, at 5am, when it has been set to charge to 100%, has been 65%, 58%, 90% and 60%.
I have noticed I've been offline a bit, when manually discharging, but it has not lasted long.
This is the first problem, apart from forced discharge, since it was installed last December.
Has anybody any suggestions? Thanks!

I have also noticed the same today as my battery is only 40% in the morning but is set to 80% overnight charge.

I've just realised that when I reset the inverter settings, I didn't have to put the charging period back. It still said 2am-5am. This was obviously not the case as this morning my battery is a 4%. Will have to check if any overnight use was fro the grid or just the battery, but:
I checked the settings on my phone, also through the portal, and there were no times set for charging from the grid. I changed it to 7:30am-8:30am and it charged fine. I've set it back to 2-5 and both phone and laptop show this, so hopefully all will be back to nornal.

I should have stuck to the app on my phone, but so many people say you need to do it in the portal. Hopefully I'll have proved that wrong and it works as it should now.