Check your column, you are using DocDspExpUnitPrice.- seeing the Dsp, tells me its merely a Display Field, probably calculated…
Perhaps, you oughta be using one of these:
- ExpUnitPrice This is the unit price based on the expected quantity.
- DocExpUnitPrice This is the unit price (in customer currency) based on the expected quantity.
Perhaps we need more code to help, I see you are trying to update the Dsp in a Get method.