Battery draining and slow charging

Hello, guys I'm struggling with my Poco x3 since some time already. I have changed battery and charging port together with connectors but that gives nothing.

There are days that phone is empty for no reason in a hour, many times I saw notification about drained battery but still didn't figured out why

I noticed also that shown battery procentage is also mostly tricky, it can show 20% and after a few seconds went off because it's empty. When I put it to the charger I can see 0%

It works also in a opposite way that shows 1% but lasts for like hour.

I have original charger but I can't really use it anymore because there is another thing what I don't get. When phone is empty my original charger doesn't charge him at all. I noticed that when is empty I can't use stronger charger, It have to be something weaker.

Please can you guys help me?