qbo just took other information from other parts of the same supplier, and dropped that into the fields I had deliberately left empty.

Eg, I didn't include any information in the fields such as town, email, phone, name -----------so across the entire row, QBO just dumped random information.   Eg, a supplier called 'starbucks, QBO entered 'starbucks' in EVERY field for that supplier including email, town, etc - all the fields which I deliberately left empty.