Check inside the port with a torch for dust or lint Build up... my suggestion is to use a metal pin and gently gently GENTLY run it along the bottom inside of the charger port in circles and clean out all the grub build up. Also check another cable to see if it does the same thing as you are describing
Whilst sorting this out check whether wireless charging is available. Check how to turn it on and buy a wall plug that supports the speed, a cable that also allows the load ? 15W/25W, and a wireless charger. If paying for a usb port it might be over $100, get a quote. It involves pulling the phone apart on a heat mat so it is not something you can do easily although that would be much cheaper. There are plenty of You Tube videos on how to do it. I am considering doing this myself buying the parts (in my case also the battery) more cheaply on the internet, although a local shop is prepared to do it more cheaply if I supply the parts.
Note in my case it is for an A7 and the cost of normal repair versus replacing it is not justifiable. In your case it would be safer to have it done commercially.
