OS, Emacs version : I am on Ubuntu 24.04 using the GUI version of Emacs in the emacs-gtk package, 29.3. The bug is also reproducible for me on Emacs 30.50 on this computer. The bug may be a problem with the GNOME desktop environment or window manager rather than Emacs, but I cannot reproduce it with any other Ubuntu applications other than Emacs. Intel® Core™ i7-6700T × 8
Behavior: When Emacs is maximized, there is an invisible rectangle whose top side and left side agree with the top and left side of my monitor, whose bottom is about 70% of the distance from top of the screen to bottom, and whose right side is about 45% of the distance from the left edge of the screen to the right, and the response to a mouse click is identical to the behavior if Emacs were un-maximized, i.e., was a floating window living in the top left corner of the screen of that size and shape. A mouse click outside the invisible window causes Emacs to be minimized, and the next window comes to the front (Or, if the desktop is the only thing behind emacs, Emacs is not minimized, and the click has no effect). Clicking inside the rectangle has the expected effect. In addition to Emacs being minimized, if the click is outside the invisible window, the mouse click does not have the expected effect on the Emacs buffer (the cursor does not move). Other than this, Emacs fully behaves as expected, i.e. text wraps at the far right of the screen, not the invisible right edge of the window for mouse input. The behavior persists after disabling "Enhanced Tiling" in the Ubuntu settings and restarting the computer. The behavior persists when using the -Q flag.
I cannot reproduce the problem on a laptop which has the same operating system and Emacs version so this may be difficult to reproduce. I will supply additional information to help reproduce if requested.