When I connect the charger, the touchscreen reacts randomly or with delay and sometimes just doesn't. I use the original Nokia charger.
Have you tired another charger and high quality lead such as an Anker Premium Double Braided? May not be the problem in your case but i have had it happen to me with other brands in the past.
So try another high quality charger and cable.
Mine is fine on a Belkin charger with an Anker premium lead, if that doesn't work for you contact support i guess.
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