I hadn't used the Lessons in v3 yet, at least not on the website, but when I completed the lesson, it had a Finish vs Computer. I'm not sure if the other features are available yet or if they are being ported over. It could be they are available too but only on certain lessons.
Missing features in Chess Mentor in the new V3 format
In the old system you could get a series of hints. Here it looks like you can get only one hint, if you click again it makes the move for you. The following features seem to be missing also:
Correct piece
Correct square
Show solution
Are they still in the process of migrating all these feature or have they killed them in the new V3 version? Can someone from chess.com let us know?

Are they still in the process of migrating all these feature or have they killed them in the new V3 version? Can someone from chess.com let us know?
having similar issues choosing lessons within a course and evn choosing a course itself. i hope this reflects a work in progress and not cutting features from Mr.Mentor to accommodate new APPs? guess all we can do for now is cross our fingers... rub a rabbit's foot... and look for a shamrock

In the mean time, can we still go back to v2? And how?
I use the iOS app 99% of the time and only came to the web browser to use the key squares for the lesson. Which plainly tells me to click on that icon (even in the app, where it doesn't exist!) so I can see the highlighted square the lesson wants me to move to.
The only thing available was the lightbulb / hint button. Which I pushed in desperation, thinking it might help. So now I just have more info on how to solve it, which I already know. I just don't know what to solve for. Plus, I got dinged 15% 😕
Where are the old features such as Analysis Board, Vs Computer, Key Squares etc in Chess Mentor in the new V3 format?