Hi @gili4 ,
Use a strong light and a magnifying glass to check that the micro USB charging port enclosure hasn't got lint or dust trapped in it.
If it has, DO NOT use a metal probe to remove the debris. Use a vacuum cleaner to try and suck it out. If it refuses to dislodge, try gently using a wooden toothpick.
Also check that the 5 pins in the port are all there, are of the same length and are straight and parallel with each other.
You can also check if the USB port "feels" lose at all, indicating that it may be partially disconnected from the systemboard. To do this, plug the cable into the phone only. Then hold the phone firmly and gently (stress very gently)try to move the plug of the cable either sideways or up and down in the port enclosure and see if you can detect any movement at all in the port.