Purchase Order Tax not calculated correctly.
There is a known issue affecting ConnectWise v2017.1 where if a user creates a purchase order, with Purchase Order Tax, ConnectWise is calculating the tax amount incorrectly and passing this through to your accounting package.
As a result, Wise-Sync is adding a 'CW > Xero Balancing Adjustment' line item to Purchase Orders to match the incorrect record in ConnectWise which is where the difference is.
Until this Purchase Order Tax calculation is resolved in ConnectWise, you have the below options to resolve the issue.
a) you can remove Purchase Order Tax from the Purchase Order
b) Remove the rounding/validation line (commonly WISESYNC_ADJUSTMENT) item from the Purchase Order.
What are adjustments?
Please refer to the following knowledge-based article: https://cw.wise-sync.com/support/solutions/articles/36000041543-faq-why-are-there-adjustment-items-on-an-invoice