I am running into a scenario of PO tax update and need help understanding the functionality and if I am following the correct process. Consider the following steps in Sage 300:

• Create a PO in sage300 with amount 100+taxes (say12).
• Once PO is fully received in sage 300 with amount 100+12, Sage 300 wipes the taxes from PO which updates the PO amount to 100.
• Once this Receiving is adopted on to an invoice in Sage300, taxes are automatically added as they are associated to Items added on receiving.
• PO is fully consumed, and no status change happens in Sage300 as PO’s don’t have statuses in the ERP. 

When such a PO is imported into another system, it shows as overdrawn because the total invoice amount exceeds PO amount when PO gets updated after receiving is created. Why is it designed this way and is there a way to avoid the PO tax update upon receiving creation? Please advise. Thank you!