You want to reverse the stock postings of an inspection lot.
You use the "Reset Usage Decision" function in app Manage Usage Decisions.
However, only the UD code and the quality score are initialized. The stock postings are not reversed.

SAP S/4HANA Cloud Public Edition

This is the standard system behavior.
Due to technical restrictions, the reversal of stock postings is not supported by standard. There are many restrictions on this and also the reversal does not fit to general design. 
Since CE2208, we introduced the "Reset Usage Decision" function into app Manage Usage Decisions. However, from the help page of the app, you can see that "When you reset a usage decision, the fields for the usage decision code and the quality score are initialized. The inspection lot status is changed from UD to UDRE. Stock postings are not revoked."

As a workaround, you can only re-post the stock into the inspection stock, and then handle them in the new-generated inspection lot. All the existing material documents will remain unchanged.
Please refer to Note2695182 - Reversal of goods movements after usage decision for more information.

Manage Usage Decisions, Reset Usage Decision, stock posting, material document, reverse

, KBA , QM-FIO-IM-2CL , Quality Inspection Fiori application (Public Cloud) , QM-IM-UD-2CL , Inspection Lot Completion (Public Cloud) , Problem

SAP S/4HANA Cloud Public Edition all versions ; SAP S/4HANA Cloud all versions