SNES through Extron Crosspoint only syncs for a second

[Derf]

Hello! I just recently got an Extron Crosspoint 128 HVA and seem to have an issue with my SNES. I am using a BNC CSYNC SNES cable plugged into my Crosspoint which feeds into an OSSC. The SNES works fine with another RGBS switcher, and I verified that it is indeed using Pin 3 for CSYNC (NTSC) with a multimeter. With the Crosspoint I can see the OSSC sees the sync signal for a second and even displays a frame on my TV, but then it changes to no signal.

Any ideas what is going on here?

Edit: I think this is just an issue with the jittery sync of the SNES. A dejitter mod would probably fix this.