Why isn't my iPhone 4S charging (apparently) only in some places?

I charge the phone at home using the Apple wall adapter that came with the phone and an Amazon basics 40-pin-to-USB cable. I have been doing so for over a year (i.e. since I purchased the cable).

I was charging the phone at work with the Apple 40-pin-to-USB cable that came with the phone, connected directly to a port on my work computer. I have been doing so for at least a year as well.

About a week ago, my iPhone stopped charging at work. It continues to charge at home.

What I've tried so far (to no avail):

1. Turning off my phone.


2. Soft-resetting my phone.


3. Replacing the 40-pin-to-USB-cable with a third-party, yet certified, cable.


4. Replacing the 40-pin-to-USB-cable with another Amazon basics cable; the same cable (per Amazon) that works at home (tho not the actual same instance of that cable).


5. Connecting (all of the three) 40-pin-to-USB-cable(s) to a wall adapter.

I have not update iOS within at least month of this issue.

I'm upgrading iOS to 8.2 (from 8.1.x) now.