Solution
This behavior is expected due to the current limitations of the DPE. DPE only supports on-demand measurements for SMUs. It is designed primarily for pattern-based digital operations using NI PXIe‑657x instruments and includes support for only basic SMU functionality.
Trigger-based measurement such as acquiring readings “on measure trigger” is considered an advanced use case that DPE and InstrumentStudio are not built to handle.