inaccurate statistics in multitenant database
My suggestion with Azure SQL Database, perform index maintenance during off-hours using Ola Hallengren's scripts and after that update all columns statistics with full scan. Do not rely on automatic features on medium size databases (> 100 GB).

Here you will find steps to create elastic jobs to update indexes and statistics using Ola Hallengren's scripts.

Another way to perform maintenance of indexes and statistics can be found here using Azure Automation and PowerShell.