How to move between editing of nested blocks?

Here we go. Don’t ask me how I triggered this bug, because I was working fast… (until I wasn’t working at all, apparently):

GIF 20.02.2020 12-29-02

Quitting out of block editing and then attempting to drill down again solved it, but it keeps happening!

I don’t understand why you can’t just keep double clicking on the blocks to drill down.

(Also, as to why I’m using wireframe mode, it’s still because of this.)