@adamtomesh since cleaning does not resolve the issue, I would suggest to replace the charging board. Those boards are widely available and luckily not to costly. Just remember that you will need one that is for your exact model. Check on sites like this for an idea of what you are looking at. This is not an endorsement of the seller, just an example. To replace it, use something like this guide It is in French but browsers like Google Chrome translate these almost perfectly.
While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.