"Simulink cannot upload data to scope because it has no connected signals"

I am using Simulink Desktop Real-Time (R2020a) in external mode to interface with a National Instruments 6353 DAQ. The image above shows the subsystem responsible for data logging in my simulation. I am triggering data acquisition for a specified duration through a scope block (saveScope), which should log the save trigger and the data collected in DAQInputs, flowInputs, and commands to the workspace as a single array once the duration has elapsed. All incoming signals are of type double, and may contain NaNs (intentionally).

Upon building and compiling the system ('TurbInterface_V4'), the following warning is issued: "Simulink cannot upload data to 'TurbInterface_V4/Scope' because it has no connected signals'. When running the simulation, the signals propogate through the system as they should, as confirmed by the display block. However, the scope does not seem to be able to see in the incoming signals, and no data is logged to the workspace.

As shown in the image, the scope is definitely connected to the input signals. I've read of the real-time scope (which I realize is different from the scope block I am using) having issues seeing virtual signals, and I have tried to resolve this by 1) addng a gain block between the input signal and scope, and 2) switching the mux block immediately before the scope with a vector concatenate block (although there are many muxes upstream which I did not replace). Neither have resolved my issue.

Any help or insight into this issue would be appreciated!