Google Authenticator

How do I get the App to ask for a code when signing in to my Gmail account that I use on my cell phone?

Log into Sign in - Google Accounts.
Click on Security
Click on 2 step verification
Add device under Google prompt

I have already done that, that's what I'm trying to stop, so as I get the code from the Google Authenticator.

Has to be on a different device to what you are logging in on?

Having said that, it took about 20 minutes for Google to send me the txt when I activated 2 factor, which is now compulsory, I ended up with several txts arriving at one go all with the same code.

Curiously my phone and tablet are all authorised devices so don't seem to need a code and neither does this PC after putting in the code last Friday.

2FA or MFA can be SIM card hacked but not as easy with an Authenticator App. Providing it works. It does on all my other sites but not on the one used in my cell phone.

You need to sign out, and clear cache and cookies. You most likely enabled the setting to trust the computer, so it wont ask for your authenticator code. If your using chrome and signed in, it wont ask for it either as its a trusted device

If I use Ccleaner or clear my browser history/cache I am asked for a code on all sites. They all use Google Authenticator App except the on in my cell phone, it asks via SMS/TXT.