Intellisense Not Working in SSMS 2016
Please answer the following questions:


Can you tell us the performance tier of the Azure SQL DB you’re connecting to? Is it Basic or Standard or Premium? How many DTUs?
How many tables/views etc. do you have in the database?
Aside from IntelliSense not working, are you able to connect normally to this database, run queries and view and edit data as you expect from SSMS?


The reason behind all these questions is to understand whether you’re hitting the DTU limit for your database. It can sometimes take longer for SSMS to build the initial cache for IntelliSense and for T-SQL completions to work. While Microsoft continues to optimize them, some of the queries SSMS uses are expensive so a low DTU database with many objects may take longer to respond.

Newer version of SSMS run the most optimized queries for intellisense. And if you are using Azure Managed Instance (MI) you should go to with SSMS v18, although is still in preview has a lot of fixes for MI.