Hi mission-towel,
I have explored Ae 2024 and Ae 2025, both gave me Main Menu> Window> Maxon Studio.
I assume that you have the current Maxon App for your Maxon One subscription and that you have checked that inside the app is all set to show.
I have installed a new version of Ae, then checked with the Maxon App, and it's all fine. I can't reproduce the problem. So, sorry.
This leaves me with the following: please get in touch with Tech Support:
https://www.maxon.net/en/support-center
Fingers crossed, you are up and running in no time.
My best wishes.