When my cursor is in the developer console, and I try to hit Cmd-+ meaning, Cmd-shift-=, the zoom-in happens in the main window, rather than in the Developer Console or whatever they call what opens up when you hit Cmd-option-i
I can zoom out fine, and Cmd-0 restores the zoom level to 100%. But I can't zoom in.
How can I do that? I have an MBP 2012.
According to https://developer.mozilla.org/en-US/docs/Tools/Keyboard_shortcuts the shortcuts on macOS to zoom in and out are Cmd++ and Cmd+-.
Note that you have to focus the DevTools (e.g. by clicking into them) to make the zoom work within them.
As mentioned in a related answer, this might also be related to your keyboard layout.