Currently the @firebase/database dependency is limited to ^0.8.1 but there have been a few releases since then - mainly the new Query#startAfter and Query#endBefore methods added in 0.9.X.

I've tried upgrading yarn add firebase-admin@latest and also yarn upgrade and not getting a later @firebase/database version than 0.8.3 - but that does make sense as ^0.8.1 will only allow patch updates on the 0.8.X line...