Same problem for me happening now
it is happening with me since last year...Complained many times..But developers told me they are observing the issue but never fixed it..The only solution is to charge the device b switching it off or charge the device in a cold place without using the device
It happens only during summer time when environment temperature is high and particularly during day time. This issue happens when the device/battery temperature goes beyond 43-45°C during charging. That time you would see the charging is stuck at 68% or 70% or 75% and the charging light is toggling as green/orange. Asus didn't work on this well known issue even after repeated reportings from us. And as Punit mentioned above, thats the only temporary fix whenever you face the issue.