Expenses transactions for vendors have vanished

I am missing all previous expense transactions relating to all third party vendors that are assigned to expanse claims. All financial data history seems to have vanished for these suppliers, while normal suppliers transactions are fine.

If I drill down through a previous P&L report on a particular cost centre, I can see the vendor name listed with the financial transaction details, but when I then click the vendor name it states no financial data exists. Clicking on the 'Supplier' tab for the vendor, their financial history is also blank.

Mileage expense claims are fine.

Is it just me with this problem?