I have observed an unexpected behavior in presentation mode in Impress: Even when deselecting all Options in the Slide Show Settings (in particular, “Change slides by clicking on background”), one can still change slides (both forward and backward) by moving the mouse and simultaneously releasing the mouse button (i.e. while the mouse still moves). It seems that the direction (forward/backward) depends on the direction in which the mouse is moved.
This behavior can be easily reproduced by creating an empty presentation with 2 slides (or, in fact, even 1 slide, as it will advance to the "Click to exit presentation … " screen).
Remarkably, this does not occur with Debian’s LibreOffice (testing/7.3.1.3), but it occurs with LibreOffice on Ubuntu 22.04, as well as with the DEBs downloaded from the LibreOffice website on both Ubuntu and Debian (I have tested different versions, including 7.3.1.3, and the most recent 7.4).
Now this might be a feature or a bug, but even in the former case, it would be rather useful to know how to turn this off. Specifically, I use an external wacom tablet to point at slides during online talks, and the tablet tends to create events exactly of that type (mouse move + key release).