This error has occurred due to a recent change in the ConnectWise API, where itemID's with double spaces are being stripped to a single space when the batch results are created. This in turn results in Wise-Sync not being able to resolve the ItemID as part of the in-built validation processes.
Status: We have logged a ticket logged with ConnectWise. Ref: 5334505.
The immediate remediation is to check the Item ID in ConnectWise Products, as the item will contain a double space as part of the Product ID.
Resolution: Remove the double space and replace with a single space in ConnectWise. The record will then sync without error.