The following items are the Bug Fixes in the NI-Digital Pattern Driver 19.0.
Use of ‘source_d_replace’ opcode results in incorrect sourcing pin states
Use of the opcode can leave the digital drive disconnected for multiple cycles after a source sample is completed. Incorrect drive state of the pins will affect the next sourced sample even if that sample is in a subsequent source waveform. Vectors that are not part of a source waveform will not be affected. This condition only occurs if and when the ‘source_d_replace’ opcode is used. Source waveform functions using only the ‘source’ opcode are not affected by this issue.