Phantom Previously Billed Amount Showing Up in Contract-Based Invoices

Has anybody encountered a scenario where the have phantom amounts show up in the Previously Billed Column of a Contract-Based invoice? As you can see below in the screenshot from the billing generation, there wasn't any previously billed amounts, we billed $36,000 this period and the new billed to date somehow calculated as $94,469 (a difference of $58,469, which is showing up on our G703 form). I'm no astrophysicist, but I believe Old Total Work Completed & Stored plus Work Completed this Period plus Mat Presently Stored should equal New Total Work Completed & Stored, which in this case it does not.

The other thing that is perplexing is that the prior "Balance to Finish" is $3,686.25, which given no worked billed would indicate that's also the contract line item value, however this line has a value of $40,000, which it's had from the very beginning. If anybody has experienced this before and knows either what caused it or how to work around it, it would be extremely appreciated.