Negative Quantity Withdrawn in RESB after cancel GI

[CaioGama]

Hello experts,

The issue is as follows:

We are performing backflushes in COR6 (movement type 261) along with Goods Receipt (101).

When some raw material needs to be canceled, users are entering COR6, changing the movement type from 261 to 262, setting the quantity and batch, and saving the transaction.

This is causing a problem where the field RESB-ENMNG (quantity withdrawn) turns into a negative value.

I believe the movement itself updates the field, but the confirmation does not.

When they try to access the material document (MIGO) or enter COR6 again, it results in a termination with the error: "DYNPRO_FIELD_CONVERSION".

Is this the correct way to cancel a Goods Issue (GI) that was made to a Process Order? Note that these materials are EWM-managed (decentralized).

Please share any insights or suggestions.