It sounds like the State Department was skeptical that the new offer was bona fide, given the very small chance that a college would offer that sort of package to a student who had failed a prior U.S. program with very poor grades. The facts behind the previous F1 denial may also be relevant, as they may reinforce an impression from the USCIS that the offers are not genuine.

If you have more facts to share, particularly as to why a graduate school would grant you such a generous package after you were academically dismissed from a prior program, and in relation to the prior denial of your F1 application, please share them.