E-bike battery charger making horrible noises, only works certain outlets?
Even though the design may be CE compliant, the unfortunate reality is that cheap manufacturers will still leave out "unnecessary" circuit components or replace them with fake ones when actually building it.  (RoHS just means it's free of lead and mercury etc etc, nothing to do with quality or usability of the electrical design.)

The components that are supposed to filter and reject electromagnetic noise are common victims since they're both expensive and it "normally" works just fine without them.

So if it works fine at home but makes weird noises at work, it seems more likely there's a failing connection in the electrical power system at your work putting a lot of noise on the line, rather than a problem with your charger.  (Other than potentially failing to reject an amount of noise that other DC supplies in the building seem to be handling, whether due to a lazy design or corners being cut in assembly.)