When it’s seen as a replacement for actual social programs. For example, a “Medicine for Orphans” charity vs just having socialised, free at the point of use medicine for everyone.

when it goes towards a cause or group that is wrong. donating to a terrorist group is still charity.

You tell me

if contributions arent being used efficiently . Or there’s not transparency. Or if fluid charitable value is of the wrong form or should be non-fluid. Fluid being… money or time. Non-fluid being… direct effort to achieve goals with overall reliable success.
I am not necessarily talking about ethics.

This isn’t strictly wrong but more meaningless: when it’s done mostly for self-satisfaction. My grandfather’s second wife was like this. She was wealthy for most of her life and loved to be a patron of the arts so she could get her name on things. As The Good Place put it, you can raise all the money you want, but if your motives are impure then it doesn’t count.

Along those same lines, the “hero mentality” type of charity, where someone (often a rich white person) comes into a community and gives money but never listens to the community about what they really need.