OK, but hwat I understand you are using several chargers and it's not charging the as it should, but if you plug it to the USB port on a PC it's charging as fast as it suppose to do it, in that case it could be a problem in the software side, maybe it's only matter of an app waiting feedback from the USB.
Let me try to explain it, if you have some app activated when the USB port is connected and it's not receiving any signal from the USB (like when it's a regular charger which only sends power using 2 of the 4 pins of the USB plug) it can limit the amount of current received for the charger.
Most of the apps which can cause that are "Optimizers", also some antivirus and cleaners could do that as what they call "overcharge protection".
So try to see if you have any app related to the use of the battery.
Hopefully it can help you to solve your problem.