Note: Room doesn't support database access on the main thread unless you've called allowMainThreadQueries() on the builder because it might lock the UI for a long period of time. Asynchronous queries—queries that return instances of LiveData or Flowable—are exempt from this rule because they asynchronously run the query on a background thread when needed.
Вы читаете ответы, адресованные вам? Или англ затрудняет восприятие? Note: Room doesn't support database access on the main thread **** => unless you've called allowMainThreadQueries()