I tried to swap some coins in my Coinbase account via the Android App and discovered my account had been resticted.

Nothing to indicate why, no email from Coinbase.

Checking security settings showed I was at maximum approval. 

Strange.

The fix? 

Log into your account via a desktop web browser.

When you do you will get a pop up asking you for some extra data for account verification. This does not show up in the app.

Coinbase wants to know:

• Which country you are a citizen of.
• How much you expect to trade in the next year.
• What type of organisation you work for.

Answer those questions and your account access will be restored. 

I was able to use the App again immediately.