The Tor Browser shield hides three security levels, and for Awazon only one is correct.
What the levels do
Standard leaves scripting on. Safer disables some risky scripting. Safest turns scripting off everywhere. The levels are not about the Tor network, which is identical at each. They change what the browser does with a page once it arrives.
Why Safest
Scripting in a hostile page is the single most reliable route to break anonymity from inside the browser. Turning it off closes that route. Safest does it unconditionally.
Why Awazon still works
Awazon is built to work with scripting off. Login, browsing, checkout and messaging all function at Safest. You give up nothing you need and close the most important hole. Set the dial to Safest for the session.