My Samsung A50's battery is draining so fast. I changed with a new battery and still had the same issue. Overheating while using and draining so fast.
What might be causing this problem?
Many reasons. Overheating indicates some process is running in the background or the mobile processor not going into sleep or power save mode. You will have to see the battery power drain graph to see if they are any processes showing battery drain. If you find nothing there then your options are to hard reset the phone and see if that helps. Otherwise monitor power consumption of phone by physically monitoring power drain from battery using multimeter/External Power Supply. this is good video to understand how to do that
Are you rooted and/or over clocking the phone?
What battery did you use to replace the current one?
Do you have any liquid ingress?
Have you replaced the thermal pad/paste on the CPU heatshield?
Is it only when certain things are on? E.g Bluetooth, WiFi, low signal (mobile carrier) etc..