I agree. It should a button there offering the old interface. It may be unrelated but the copy wallet address no longer works for me. Not sure if it’s to do with the new interface or just a coincidence. Same issue on all browsers, chrome, firefox and brave
In recent older versions, you can find the Portfolio entry here.
In earlier versions, Portfolio was in the area under Assets/NFT/Activity.
If you can’t see it, maybe the version is too old and the portfolio feature is not live yet.