I’m an iPhone tech. From my experience, it tends to be software glitch prior to suspecting the Tristar IC chip. It is very unlikely that chip gets damaged so I would ALWAYS suspect software first if not the cable or charge port. I worked for Verizon tech support for a couple years and we saw any number of ‘random’ software glitches. Most of the time it’s related to pending software update. I’ve worked on several different model iPhones (not X or newer) where I’ve installed new charge ports, tried different known-good cables, etc.
First step BEFORE having charge port replaced (unless it's loose or has side-to-side play) is to plug into iTunes and restore software. There is very good chance this will fix it without having to wipe phone lose data. Full factory reset is next option. Obviously you should update software before anything if an update is available.
I figured it our the hard way after trying multiple batteries, chargers, and 2 new charge ports. I deduced that if it’s not hardware problem, then the super-glitchy Apply software is the fault. My personal opinion is this is intentional so a certain percentage of customers will ultimately buy a new phone instead of fixing. Software being the culprit or downfall for a phone is very stupid. Good thing there’s iTunes, but for real though these issues should never occur.
Bottom Line: If cable/chargers work for other devices, Always assume software issue first. Troubleshoot hardware next.