The "Enable Message Composer" action is not working due to a confirmed bug on Facebook side.
Also if you use the action "Set User Persistent Menu", the user will not see the "bot persistent menu" again when you change the user persistent menu back.
Also if you set a User Persistent Menu, the user will not see the bot menu again due to the below Facebook bug
https://developers.facebook.com/support/bugs/566082604760902