Please perform the following steps to resolve the issue:
For battery drainage issue follow the given link: http://www.samsung.com/in/support/skp/faq/1101689
1- Charge the device with the original charger.
2- Follow standard battery charging procedure (charge a fully discharged the battery in Switch-off mode up to 120 ~ 150 min)
3- Perform Interactive checks through the Samsung Members Application (Samsung Members > Get Help > Interactive checks > charger/USB).
For other mentioned issues, register your concern in Samsung Members Application (Open Samsung Members Application > click on “+“icon > send feedback > error report/ask questions).
Team Samsung Members
Same is happening with me also, my M30s is only 1.5 months old and recently have been experiencing a similar issue of battery getting recharged really slow(took 3hrs to get it to 0 to 40%)....it wasn't happening previously(before it could charge to 100% in 2-2.5hrs or so) it's just happening since the last week....
**have tried the suggestion of the moderators above...none of them seem to work, no improvement 👎
Hence I've sent an error report with the issue...perhaps they can dig into this and help 🛎📢