Invoicing Order - Services Change Order each time they are saved

Roz @ Finch reported this issue.... Master order is Invoice - Xero Line Item Order to show:
1)Services
2) Tasks (where billable, drag and drop tasks so they are ordered correctly within this block)
3) Products
4) Materials

However within services if you have more than one line of services every time you save it the order changes - see example on https://prod.jobflow.nz/#/jobs/1806 ( logged in as S2usera, job #16-0003...so you may have the right order you change to invoice and save and it changes the order sent through to Xero.

Not a blocker because Xero allows the invoice lines to be reordered with a drag and drop there but be nice to fix this random order!