Yes, Masa is right. Please focus on URLs starting with "/sap/opu/odata/" as these are the OData services. For reference, I have attached a screenshot of the URLs that are called on our system when a leave request is approved:
On a side note: "i18n_en_US.properties NOT found" is related to language files... You probably have set your language to "en_US", while the language file is only available in "en". This is no problem as SAPUI5 will automatically chose a fallback version.