Thanks for the further explanation of background. I appreciate you never chose to be a JW yourself, nevertheless interaction with JWs may be fairly described as more than academic.
I can’t show it written down anywhere, but I can certainly say that my experience is that giving to charity was frowned upon. The basic attitude was that money donated to charity could be better spent on the “world wide work”. Because what charity could be more important than the good news? If you really believe the JW worldview then they would have a point.
This was not a hard rule. Some openly donated and even volunteered for charities. But those doing this seemed to need to “justify” their actions to others.