Web Service Error "The system failed to commit the BatchModule row"

I have an integration (roughly 4 years old) that I used the Acumatica.RESTClient to get started a while back. While not this exact version, it was an older version available at the time: https://github.com/Acumatica/AcumaticaRESTAPIClientForCSharp

All of a sudden recently an issue popped up in the live tenant when using this tool to submit to the web services just creating a very basic Journal Transaction. The payload includes the Module (GL), LedgerID (ACTUAL), Description, TransactionDate, Hold (false), and finally Details (details include Account, Subaccount, DebitAmount, and CreditAmount).

When sending to the transaction using the Acumatica.RESTClient code, it will fail in the live tenant. I get this response from the web services:
 

 An error has occurred. : Operation failed : {
  "message": "An error has occurred.",
  "exceptionMessage": "The system failed to commit the BatchModule row.",
  "exceptionType": "PX.Data.PXException",
  "stackTrace": "   at PX.Api.SyImportProcessor.SyStep.CommitChangesInt(Object itemToBypass, PXFilterRow[] targetConditions, PXFilterRow[] filtersForAction, SyImportRowResult importResult) in C:\\build\\code_repo\\NetTools\\PX.Data\\Api\\Export\\SyImport\\ImportProcessor.cs:line 3776\r\n   at PX.Api.SyImportProcessor.SyStep.CommitChanges(Object& itemToBypass, PXFilterRow[] targetConditions, PXFilterRow[] filtersForAction) in C:\\build\\code_repo\\NetTools\\PX.Data\\Api\\Export\\SyImport\\ImportProcessor.cs:line 5530\r\n   at PX.Api.SyImportProcessor.ExportTableHelper.ExportTable(CancellationToken token) in C:\\build\\code_repo\\NetTools\\PX.Data\\Api\\Export\\SyImport\\ImportProcessor.cs:line 1443"

When I swap over in the same instance to the test tenant it works. This would leave me to believe it’s some sort of system-wide setting, but it’s not like there are a ton of different settings for the Finance module.

Here is the JSON payload pulled from the integration that I used which I pulled from the integration when it sends (even confirmed the data with Wireshark because I was skeptical, lol):

{
	"Description":{"value":"GL Export Inventory Update"},
	"Details":
	[
		{"Account":{"value":"5100"},"CreditAmount":{"value":12345.0000},"DebitAmount":{"value":0.0},"Subaccount":{"value":"0000"}},
		{"Account":{"value":"1300"},"CreditAmount":{"value":0.0},"DebitAmount":{"value":12345.0000},"Subaccount":{"value":"0000"}}
	],
	"Hold":{"value":false},
	"Module":{"value":"GL"},
	"TransactionDate":{"value":"2026-03-31T07:39:20"}
}

When I test via PostMan with the above payload/link, it works in test but not live (the strange part is it did actually work in live originally when sending via Postman which is why I mention the github client, but stopped working at some point and I don’t know why). This is the URL for my local instance testing with uploaded snapshots from the Acumatica hosted instance: http://localhost/[INSTANCENAME]/entity/[ENDPOINTNAME]/[ENDPOINTVERSION]/JournalTransaction

And I’ve also tried to just manually create the transaction in the UI and only enter the information I’m passing and have no issues. No customizations are in this instance. They did update to 2025R2 a couple of weeks ago, but the issue wasn’t a problem immediately and only started acting up roughly a week after the update, so I’m not sure that would be related.

I’m at a total loss for what this problem is. I’m guessing there has to be a setting change and something is required when sending now versus before. Anyone have any thoughts?