HTC one M7 charging only from power bank

I have had my m7 for almost two years and a half now. I faced a problem yesterday that my phone charges very slowly when connected to AC power output or PC USB even if i put it on airplane mode, and even discharges when not on airplane mode.
It charges normally only when connected to my charged power bank.
My power bank charges normally with the same cables and chargers.

Any thoughts on this issue would be appreciated. Thanks!