@asus Some how i believe it is a software issue as the issue is getting resolved after changing the ports. (the software/firmware that prevents the damage of battery due to over charging).
I have also faced the same issue. Below is my case and solution.Case: My batery drained and i used my friend's fast charger as i did not have my asus rog phone 2 charger nearby. Nextday i forgot to take my charger to office and the battery went to 3 ...