Hi Faas,

I have not tried Jupyter with WL and I don't know what the limitations are. Some things to try and narrow down the issue. Doubt it has anything to do with your network.

The dataset includes images and references to other entities. Try simpler queries

PersonData[Entity["Person", "AlbertEinstein::6tb7g"]] // CanonicalName
PersonData[Entity["Person", "AlbertEinstein::6tb7g"]]
PersonData[Entity["Person", "AlbertEinstein::6tb7g"]]["Properties"] // CanonicalName
PersonData[Entity["Person", "AlbertEinstein::6tb7g"]]["Properties"] 
PersonData[Entity["Person", "AlbertEinstein::6tb7g"]]["Children"]
PersonData[Entity["Person", "AlbertEinstein::6tb7g"]]["Image"]

Try other datasets

WeatherData[Here, "Temperature", {2021, 3}] // DateListPlot

I am curious, what are you going to use Java for on this data? Can it be done in WL instead?

hmm, that too, does not work for me. it simple returns this (see picture). Can this have something to do with that im using jupyter notebook and am on a home network?

EDIT:: when i run that in the engine itself, it DOES work. i still need this to embed it in java though... any ideas on how i can fix this?