Improved stock count operation in POS and 'Allow posting stock counts' POS position permissions

[RethaLam]

We turned on the Feature “Improved stock count operation in POS” and are testing it on the tier-2 sandbox.
We also decided to allow a test user via his POS position permissions to post stock counts.

When we tried to post the stock count, we get the error : "Nullable object must have a value". It is on POS operation 808.
I cannot find anything on the POS side that could cause the error, so I looked on my Dev box where I also get the error and in the event viewer I see the error:

"Generic structured logging event with 'Information' severity was logged. Event name: Microsoft.Dynamics.Commerce.Runtime.Services.InventoryDocumentService+Events.InventoryDocumentProcessingFailedInHQ. Message: Inventory document 2a267e4e-22fc-4d24-a631-1fc20163b2ce processing failed in HQ, operationType: PostStockCounting, commitRequestId: ec054f85-4506-4ee3-9218-7700087e0cc0, errorMessage: 'Nullable object must have a value.'. "

I was searching for the PostStockCounting operation but could not find it anywhere in the AOT.
There is a RetailInventoryDocmentType base enum, but it only has StockCounting as an element, not PostStockCounting.

We are on v10.0.30.

The status on the "Active" journal also shows "Processing failed".

So, are we not supposed to turn on the "Allow posting stock counts" in the POS permissions for the improved stock count feature?
It is definitely not that we do not have the correct code because this feature came in with v10.0.24 and we are already on v10.0.30.

To duplicate, turn on the feature and turn on the POS permission to allow post of stock count and run the appropriate distribution schedule jobs to push to the channel DB.
Then create a stock count, I selected to create a Physical count journal.
I added a product, selected a location and added a quantity. Then I clicked on the Submit button and I got the message that it was successfully committed to HQ.
Then it returned me to the stock count view with the list of active journals. I selected my journal and clicked on view details. I marked my product and clicked on Post.
I was shown the below message and was given the opportunity to still post or cancel.
"By selecting Post, the counting results will be posted directly. No further edits can be made to this journal. Please ensure all required data has been entered."
I clicked on Post. This is when I get the error: "Nullable object must have a value."
If I click on More tools > Developer tools to see the error in the browser I see the following:

"
The Retail Server Request with request id '876c99e0-2590-759d-8930-44f8fca79de9' and request url '<....>/Commerce/InventoryInboundOutboundDocuments/SearchLines?$top=1&api-version=7.3' succeeded. Status code 200, Time elapsed 207.29999999701977 ms.
Diagnostics.TypeScriptCore.js:580 Navigating from: 'InventoryDocumentStockCountingListView'. Navigating to 'InventoryDocumentStockCountingWorkingView'. Correlation Id: '72065e59-a8ab-056b-3caf-176a71841caf'.
Diagnostics.TypeScriptCore.js:580 Page Loaded: InventoryDocumentStockCountingWorkingView.
Diagnostics.TypeScriptCore.js:572 An error was thrown while executing a message handler for message type 'DocumentLinesSelectionCleared'. Error Name: TypeError. Error Message: 'Cannot read properties of undefined (reading 'OperationTypeValue')'.
DebuggingConsoleSink.writeEvent @ Diagnostics.TypeScriptCore.js:572
"
Any help with this is much appreciated.