I gotten my apple watch replaced three time from apple care with the same issue every time i put my apple watch to charge the battery percentage goes down while it charges.At other times the battery percentages freezes and stays at the same battery percentage for a while and it does not go up.I also have the metal and the plastic charger to confirm if its the charger.I did all the steps setting the watch as new and setting the iphone as new and i got the iphone replaced also. What can be causing this issue ? I already got the watch replaced three times.