I don't know much about this new explorer tool, but it's based off of USASpending.gov which is a bit fickle...which is to be expected given the messiness of the data involved (companies have varied names, subsidiaries etc., among other real-life complexities).

But you can do an "advanced search" by registered company name, and this is what comes up for "Microsoft" -- probably doesn't include all of its subsidiaries that don't have "Microsoft" in the name: ~$1.4 billion in awarded contracts

https://www.usaspending.gov/Pages/AdvancedSearch.aspx?sub=y&...

edit: Oh I know the reason for the discrepancy...the homepage of the beta app says it's only partial data:

> Added more years of contract data to now include 2011 - 2015