The B-2 Spirit has never been officially confirmed to have been shot down according to any credible reports. Nevertheless, there have been several crashes involving the B-2 Spirit, all attributed to accidents or mechanical failures rather than enemy fire. Below is a summary of the known incidents:

 B-2 Crash Incidents:
Andersen Air Force Base, Guam (February 23, 2008)
Cause: Moisture in the aircraft’s sensors resulted in incorrect readings during takeoff, which led to a stall.
Outcome: The aircraft crashed shortly after takeoff, but both crew members ejected safely.

Was it shot down?  No — it was solely a technical failure.

Whiteman Air Force Base, Missouri (September 14, 2021)
Cause: A crash occurred during landing. Details are sparse, but it was not a result of enemy action.
Outcome: The aircraft sustained damage, prompting an investigation.