This appears to be a customized version of the Portfolio Value report.
The first thing I would do would be to start with the built-in report, apply the same customizations, and see if that fixes the problem.
You could also back up your data ust in case, then do a File > Validate and Repair.
Please let us know if the problem persists.
im having the same problem….i've added all the reported transactions in a calculator and Excel and get a small differance from the total shown in the report..