One of our customers does a daily import of Customers and Vendors from another 3rd party software. We set up the AP Vendor import scenario with a sync type of "Incremental - New Only" because they regularly export an existing vendor from the 3rd party software regularly. Our thought was that this setting meant it would only import new vendors. However, over time, a user noticed a field was getting changed after they imported vendors, and this one vendor was in the source file. After testing, we found out that the import was the cause of the issue and that it was reimporting the vendor.
After working with Acumatica Support, it was determined that the import is working as designed, and the Incremental - New Only and Incremental - All Records sync types are based off of new versions of the original source file, and not whether or not the record already existed in Acumatica.
I am requesting updates to the sync types so that the Incremental - New Only (or a new, additional option) means the scenario will only import new records, and if line is an existing record in Acumatica, i.e. Vendor ID or Customer ID, then that line will get skipped.