CircleCI 2.0 mac image hangs when running jest

We are migrating to CircleCI 2.0 and evenrything seemed well, but suddenly a few days ago (we found out on monday) our tests step stopped working, just hanging in middle of the process with no message or issue being reported and eventually timeout.

We are trying to run jest 2.0.4 with a few tests on a mac xcode 8.3.3 image. Running on local it does not seem to consume too much memory. We tried to rerun a previously successful instance, but we still had the same problem.

Already tried to run with --runOnBand and --maxWorkers (that had previously helped with another issue), but had no change.

Does anyone know what may be happening?