Niagara particles culled outside first nDisplay mosaic

Hi!

We have a problem with a Niagara system whose particles seems to be culled outside the first nDisplay mosaic. Particles are visible in the first mosaic, and some of them in an adjacent mosaic, but it seems to be a cut off from the frustum of the first mosaic.

We have checked particle bounds, which seems correct.

Any ideas on how to proceed with this?