I have the following xml that I'm sending to the method DoItUsernamePwd and it's updating everything but the Sizes and SizeSKUModifiers. Can anyone explain why?

<AspDotNetStorefrontImport Version=\"7.1\"><Product Action=\"Update\" GUID=\"b40ff59f-75bb-4636-ba8e-5b45cc507c49\"><Name>Round 3-Prong Basket Setting</Name><Description><![CDATA[<p>The series RT round, 3-prong, basket setting (metal mold cast) is available in sizes from 1.0mm to 6.0mm in 14-karat white gold and 14-karat yellow gold metals.</p> ]]></Description><SKU>RT</SKU><Display><XmlPackage>product.variantsingrid.xm l.config</XmlPackage></Display><Published>true</Published><ColWidth>4</ColWidth><SizeOptionPrompt>Round MM Size</SizeOptionPrompt><ColorOptionPrompt>Metal Quality</ColorOptionPrompt><ProductTypeID>100</ProductTypeID><Variants><Variant Action=\"Update\" GUID=\"e80acd12-7741-4371-90e7-63f062c6178e\"><Name>14KT White</Name><IsDefault>1</IsDefault><DisplayOrder>1</DisplayOrder><Sizes>1.0mm (.005ct),2.0mm (.03ct),2.5mm (.06ct),3.0mm (.10ct),3.5mm (.16ct),4.0mm (.25ct),4.5mm (.33ct),5.0mm (.50ct),5.5mm (.63ct),6.0mm (.75ct)</Sizes><SizeSKUModifiers>-1W,-2W,-2.5W,-3W,-3.5W,-4W,-4.5W,-5W,-5.5W,-6W</Si
zeSKUModifiers></Variant><Variant Action=\"Update\" GUID=\"a75d0533-6c0c-445b-b5f6-5372404a2ce7\"><Name>14KT Yellow</Name><IsDefault>0</IsDefault><DisplayOrder>2</DisplayOrder><Sizes>1.0mm (.005ct),2.0mm (.03ct),2.5mm (.06ct),3.0mm (.10ct),3.5mm (.16ct),4.0mm (.25ct),4.5mm (.33ct),5.0mm (.50ct),5.5mm (.63ct),6.0mm (.75ct)</Sizes><SizeSKUModifiers>-1Y,-2Y,-2.5Y,-3Y,-3.5Y,-4Y,-4.5Y,-5Y,-5.5Y,-6Y</SizeSKUModifiers></Variant></Variants><Mappings><Entity Action=\"Add\" EntityType=\"Manufacturer\" Name=\"ROSECO\" DisplayOrder=\"1\" /><Entity Action=\"Add\" EntityType=\"Category\" ID=\"4\" DisplayOrder=\"1\" /></Mappings></Product><Product Action=\"Update\" GUID=\"d1819eb1-8a79-4bf9-8da6-6062e729dd3b\"><Name>Round 3-Prong Basket Setting</Name><Description><![CDATA[<p>The series RTR round, 3-prong, basket setting (casted) is available in sizes from 2.0mm to 6.0mm in 14-karat white gold, 14-karat yellow gold, and platinum metals.</p> ]]></Description><SKU>RTR</SKU><Display><XmlPackage>product.variantsingrid.xm l.config
</XmlPackage></Display><Published>true</Published><ColWidth>4</ColWidth><SizeOptionPrompt>Round MM Size</SizeOptionPrompt><ColorOptionPrompt>Metal Quality</ColorOptionPrompt><ProductTypeID>100</ProductTypeID><Variants><Variant Action=\"Update\" GUID=\"6c62e81c-e0ed-4d15-a747-8141756f14e5\"><Name>14KT White</Name><IsDefault>1</IsDefault><DisplayOrder>1</DisplayOrder><Sizes>2.0mm (.03ct),2.5mm (.06ct),3.0mm (.10ct),3.5mm (.16ct),4.0mm (.25ct),4.5mm (.33ct),5.0mm (.50ct),5.5mm (.63ct),6.0mm (.75ct)</Sizes><SizeSKUModifiers>-2W,-2.5W,-3W,-3.5W,-4W,-4.5W,-5W,-5.5W,-6W</SizeSKUModifiers></Variant><Variant Action=\"Update\" GUID=\"ac1bfb67-9edc-4476-940f-f974d2e8e171\"><Name>14KT Yellow</Name><IsDefault>0</IsDefault><DisplayOrder>2</DisplayOrder><Sizes>2.0mm (.03ct),2.5mm (.06ct),3.0mm (.10ct),3.5mm (.16ct),4.0mm (.25ct),4.5mm (.33ct),5.0mm (.50ct),5.5mm (.63ct),6.0mm (.75ct)</Sizes><SizeSKUModifiers>-2Y,-2.5Y,-3Y,-3.5Y,-4Y,-4.5Y,-5Y,-5.5Y,-6Y</SizeSKUModifiers></Variant><Variant Action=\"Update\" GUID=\"7f1a3598-3b4
5-4345-9689-405b6642eb32\"><Name>Platinum</Name><IsDefault>0</IsDefault><DisplayOrder>3</DisplayOrder><Sizes>2.0mm (.03ct),2.5mm (.06ct),3.0mm (.10ct),3.5mm (.16ct),4.0mm (.25ct),4.5mm (.33ct),5.0mm (.50ct),5.5mm (.63ct),6.0mm (.75ct)</Sizes><SizeSKUModifiers>-2PT,-2.5PT,-3PT,-3.5PT,-4PT,-4.5PT,-5PT,-5.5PT,-6PT</SizeSKUModifiers></Variant></Variants><Mappings><Entity Action=\"Add\" EntityType=\"Manufacturer\" Name=\"ROSECO\" DisplayOrder=\"1\" /><Entity Action=\"Add\" EntityType=\"Category\" ID=\"4\" DisplayOrder=\"2\" /></Mappings></Product></AspDotNetStorefrontImport>