Sales Invoice Screen - Totals Field - Multiple Figures

New Manager user here, I’m in the process of testing and migrating records from MYOB. Some I’ve created with batch imports, some I’ve created manually.

I’ve recreated a subset of Sales Invoices and have encountered an issue in the summary view of the Sales Invoices screen - the column total does not consistently display a single figure, it seems to group the figures arbitrarily. This also affects the Sales Invoice Totals by Customer report, with some figures appearing outside the main group, and not included in the total.

If I edit and save a Sales Invoice in the excluded group, it is then reflected in the aggregated total. If I do a batch update of all Sales Invoices, without changing any data, I get a single aggregated total, however the problem re-appears upon restart. Sometimes the aggregated figures change when I leave the Sales Invoice screen, perform another action, then return.

Any ideas? Indicative screenshot below with identifying columns hidden (I’m only allowed to upload one file)

(great product BTW - can’t wait to move onto it)

Cheers,

Simon