I have pro account and previous model "Argon" still not available on my account.

I have it on both web and agy, but you know when you wait for something and in the end it turns out to be not that good...

Mine showed up after clearing cache for some reason.

is it on web interface or antigravity ?

gemini.google.com (Pro plan).

AGY never even update often, and only has gemini 3.8 flash (for Google model).