Preprocessing callback is executed prematurely

[gutjuri]

Consider the following piece of code:

console.log("queueing preprocessing");
var t_start_pp = process.hrtime.bigint();
jiffClient
  .preprocessing("cdiv", 6, null, null, compute_parties, compute_parties)
  .then(console.log("finished preprocessing for cdiv"));
jiffClient.executePreprocessing(() => {
  var t_end_pp = process.hrtime.bigint();
  console.log(
    `performed preprocessing in ${
      Number(t_end_pp - t_start_pp) / 1000000
    } ms`
  );
  compute.bind(null, jiffClient)();
});

As the documentation states that the return value is "a promise that is resolved when preprocessing is completed, null if this is called by a party that is neither a compute nor receiver party", one would expect that the programme would print finished preprocessing for cdiv after all preprocessing is finished.
However, when executing the programme I observe that finished preprocessing for cdiv is printed almost immediately, while preprocessing continues.
The next log message performed preprocessing in [...] is only printed after preprocessing is actually finished, which is several minutes later.

Expected behaviour:

finished preprocessing for cdiv should be printed after all preprocessing is completed, i.e. the promise returned by preprocessing() should resolve after all preprocessing operations triggered by the corresponding call to preprocessing() are completed.