Sometimes OBS doesn't record Zoom windows when capturing displays

[anothereditor]

I'm trying to help someone record their Zoom meetings using OBS Studio. I suggested using OBS Studio because they need to capture 2 shared screens, and Zoom only gives you one active shared screen at a time in their recording. This person uses dual monitors to watch both shared screens on the call, so we're using a canvas that's twice as wide as the monitor resolution with 2 display sources side by side.

We've successfully recorded both displays multiple times now. However, recently, OBS Studio has malfunctioned in two main ways:

1. Sometimes, OBS Studio won't show the Zoom windows, even though those windows are visible on the monitors. The OBS preview and the recorded file will show whatever windows are underneath the Zoom windows. Sometimes we've been able to fix this by restarting OBS Studio.
2. Other times, restarting OBS Studio will restore only one monitor, and the scene will show a duplicate of that monitor instead of the other monitor. In order to fix this, we've had to remove the sources entirely, then add them back to the scene.

Can anyone help me understand what might be causing this to happen? I'm a Windows user myself, so it's harder for me to test what might be going wrong on this person's Mac.