JSON parser in Dataflow incorrectly parsing small values

In Power Query desktop, the JSON parser correctly runs the following example:

let
    Source = Json.Document("{ a: 0.000068 }")
in
    Source

Resulting in: a:6.8E-05

Unfortunately the same query in Dataflow results in: a: 0

Of course, putting the value in quotes forces it to be a string and it is returned correctly in both products. However, the JSON parser should not be rounding numeric values to zero and should be using the same JSON parser so we don't get inconsistencies in parsing.