Your plant or irrigation schedule is showing the wrong symbol for an object in your drawing. For example, a plant symbol that shows up in the Plant Schedule differs from the symbol for the same plant as it appears in the drawing.
You have the incorrect block for that schedule symbol in your LandFX folder.
Delete the existing block for the errant symbol in the LandFX folder.
Delete your schedule, and purge it from the drawing by typing PRG in the Command line and pressing Enter. Run the schedule again. It should now be correct.