Data is different when uploading and importing via the Anaplan web application compared to performing the same data operation in OneCloud.
Oftentimes, the Anaplan Connection is configured to use a different user than the user who is interactively logged into the Anaplan web application. When this occurs, any data uploaded via the user configured in the OneCloud Connection could be different from the data uploaded interactively by an Anaplan user directly from within the Anaplan web application.
If you manually upload data and run an Anaplan Import Action (or Process that contains an Import Action), the results that you get manually may be different from what you see when performing the same operation in OneCloud.
OneCloud leverages the Anaplan API. When performing operations via the API, Anaplan will use different source files for importing into Lists and Modules than the default Data Source or the Data Source that is manually uploaded. This article on Anaplan's support page provides additional insight: https://help.anaplan.com/ebc01b56-7b57-4e36-93de-acfdb75a8441-Overview-of-Private-and-Default-Files.
Configure the OneCloud Anaplan Connection to be the same users that is interactively uploading data to the Anaplan web application.
Export identical data from the source and manually upload this data to Anaplan. Note that this solution will invariably have different data as the interactively uploaded data becomes stale.