I've been experiencing that same problem. It first originated when I plugged the g7 in overnight to charge and came back to a totally dead battery and the phone wouldn't turn on or indicate the charging cable contact visible by a white blinking light in the upper right top. I messed around and finally was able to charge it enough to reboot it by holding the down volume and power button simultaneously for a good 15 seconds and just selected restart in safe mode. After examining the situation I noticed a part of the center housing frame directly underneath the charging port was totally missing, broken off so I chalked the charging issue up to that. Ordered and replaced the port itself and used epoxy to build up the frame by shaping it after it hardened then reassembled the phone with the new charging port board section (which took me a long time to find online and not an exact replacement but after earning myself a degree in hardware purpose I purchased my best chance of choice of replacement part) . After conversing with Motorola to get an estimate for repair I was quoted a price of $165 for the repair which included the mid frame replacement but to purchase a brand new g7 was the same price as the repair so I had nothing to loose by taking on the project myself without any previous knowledge or experience with a non-removable battery and back. So here I am several months later experiencing the same issue as before and now thinking its not a hardware issue (although I'm sure its t helping matters) its not the charging port itself because I experienced the same identical issue with the OEM board and port as I did with an after market Chinese replacement board and port. It worked great at first when new and when the pert was newly replace so I'm not sure but have a difficult time believing its program issue because it either works or it doesn't when its software issue but again the only exposure to any of the phones components and technical functionality comes from troubleshooting this charging port issue. However while aggravatingly messing around I took notice yo a piece of black thin rubber that covers the very back of the inside of the port and is cut out around 4 circular contact faces and is loose at the side or vertical side looking at the port went the center mid section with the pins is at a horizontal view and when tinkered with , contact improved slightly but only for 2 or 3 times of plugging in the cord. My next thought is to replace the charging board again, purchasing an adapter (male c to female c) and permanently securing it as an unremovable appendage that extends out of the bottom of the phone or doing the same permanent connecting approach with a wireless charging dongle but either way the fast charging capabilities will most likely disappear.