Dual-CSI Nano unexplainably missing frames

Nano B01
Raspi Cam v2 (IMX 219)

When I run the cameras individually they are able to get up to 720p@120hz, but when I both cameras together one camera only gets about 2/3 of the fps it is supposed to get (and the other one gets the full fps). I tried reducing the resolution to 480p, reducing the fps to 60hz, and a variety of different settings, but the result is still the same.

I don’t understand what could be causing this bottleneck. Can someone please help me out?

Here is the pipeline I’m using:
gst-launch-1.0 nvarguscamerasrc sensor_id=0 num-buffers=2000 aelock=true gainrange=“1 1” ispdigitalgainrange=“1 1” exposuretimerange=“1000000 1000000” exposurecompensation=-2 sensor-mode=4 ! ‘video/x-raw(memory:NVMM),width=1280, height=720, framerate=60/1, format=NV12’ ! omxh264enc ! qtmux ! filesink location=test_60fps_0.mp4 -e nvarguscamerasrc sensor_id=1 num-buffers=2000 aelock=true gainrange=“1 1” ispdigitalgainrange=“1 1” exposuretimerange=“1000000 1000000” exposurecompensation=-2 sensor-mode=4 ! ‘video/x-raw(memory:NVMM),width=1280, height=720, framerate=60/1, format=NV12’ ! omxh264enc ! qtmux ! filesink location=test_60fps_1.mp4 -e

Should be the duplicate topic with