Please ask your question in GITHUB as the team that works on that control actively work there. You are asking in the Windows Maps Q&A rather than in https://github.com/microsoft/MapsSDK-Unity/issues?q=is%3Aissue+is%3Aclosed (Be sure to check the closed issues).
NOTE: Hololens & the Maps Unity SDK only supports certain versions of Unity. Chances are your version of Unity is the issue.