SNAP cannot process VV and VH at the same time?

Hello users! I have been using the S1 and SNAP toolbox for a while now, and have never been able to process both VV and VH bands in the same Graph. For example, see the attached figure. When only one polarization is selected, the process runs fine. When both polarizations are selected, SNAP hangs and eventually crashes. The same problem existed in the S1 toolbox. Any solutions?