The first thing you should do is go to the Billable Expenses tab and look at the status of your billable expenses. A positive balance in Billable expenses indicates something has not been invoiced.
The second thing is to drill down on the 48,500.00 figure to see what contributes to it and why.
Third, you should look in the Customers tab for uninvoiced expenses. If you find any, look for the reason.
Note that there have been quite a few changes to Billable Expenses since your last version, including the way they display on the profit and loss statement. This began with v19.12.5 and was discussed in the January 2020 newsletter. See the Guides about recording and invoicing billable expenses.
Out of curiosity, did you end up with anything in Suspense? I suspect you may have orphaned accounts or account assignments that are preventing your billable expenses from showing as being properly invoiced.