Payables Standard Invoice Import failing despite valid files

Summary:

Third party invoice feeder system FBDI batches failing to load from around 13/10/23

Feeder system send invoice batches with file names suffixed with client id & time date stamp (DDMMYYYYHHMMSS) e.g.

ApInvoicesInterface_778_11102023120118.csv & ApInvoiceLinesInterface_778_11102023120118.csv

Invoices following this pattern have loaded previously without issue however this appears to have stopped from around 13/10/23.

Testing appears to indicate issue is related to the suffixs as if filename suffix is reduced for instance to remove the SS from time date stamp then the file loads without issue.

Has there been a change to the allowable load parameters, as I can find no details on file name requirments @