Click twice quickly on the left arrow in the titlebar of the window – the one that looks like this:
Clicking two (or more) times in quick succession on the left arrow should simply page back through the history of pages you’ve visited, and not maximise the window – the window should only maximise if you double click on the title bar outside of the arrows.
The window is maximised. If the window is already maximised, then the window size is restored.
Mac OS 10.15.7
Obsidian version 0.12.13
The same thing happens when clicking twice quickly on the right arrow as well.
Just to help narrow down the bug, I tried the same thing on Windows 10. On Windows 10, double clicking both backward and forward arrows work correctly and the window does not maximize. So this seems to be something Mac specific.
Double clicking the title bar to maximize the window is a standard OS behaviour also in Windows and Xubuntu. What I meant with “So this seems to be something Mac specific.” was that the bug seems to be Mac specific, meaning that the bug only occurs on Mac.