ODMSP: There's a discrepancy between source an target amount of files and/or sizes (4372982)

There are multiple factors, that may affect the final outcome. Before verifying what is causing discrepancies, please review SharePoint migration limitations, that outlined in this document: On Demand Migration Current - User Guide (quest.com)

In addition to that, the following factors may affect it:

• are all versions migrated or only the latest?
• are there 0 byte size files?
• also include recycle bin contents that accumulates with use 

Lastly, after the migration process, Microsoft is running an indexing process in the backend. We've observed delays of over 24 hours in reported statistics until actual sizes are reported.