Let me join this thread and explain why there's no deduction in your Work-In-Progress (WIP) account.
To start, the Bill you've generated will impact the Accounts Payable, not your WIP account directly. The bill will depend on the Category or Account associated with the items you've selected.
If you want to transfer or reduce the WIP account, consider using a Journal Entry (JE). When using JE, I suggest seeking assistance from an accountant to set this up properly.
The Community is always open if you have further concerns about closing out your WIP account. Keep safe.