poco x3 pro not charging

Hello, please tell me what the problem could be. I decided to change the battery, put a cheap Chinese one, after it discharged to 0, the phone always shows 1% charge (only the first 30 seconds it shows 100%, then instantly drops to 1), even on the old battery now it is like this, even after a full charge through the lpb. The charging current through the phone is now 20-50 milliamps! Although before it was several thousand. I have already changed the lower charging board and the interboard cable, it did not help. The contacts on both the cable and the board look intact. Thanks in advance for your advice