Normally when you pan or scroll with a mouse wheel, rotating wheel down causes scrolling down or right. Every program I have installed works this way, including GIMP and Inkscape. But LibreCAD for some reason works the other way around - rotating the wheel down scrolls up or left. Also I don't think it was always like that and it've worked normally before.
So what could've happened and how I can make it work normal? I don't see any 'invert mouse wheel direction' option.
This is true for both repository version of LibreCAD and 2.2th I've just compiled from source. Xubuntu 18.04.
I use version 2.2.0-rc1 on Windows. I'm not sure if this is what you mean but when rotating the mouse wheel the screen will zoom differently depending on where the pointer is located on the screen. When I rotate the mouse wheel the drawing will zoom in or out. To pan in any direction I depress and hold the mouse wheel and the cursor turns into a hand. Then just move the screen around. Hope this helps.
Ctrl + rotate wheel down causes an object on the screen to move down while
the slider bar on the right moves up.
Shift + rotate wheel down causes the object to move to the right and the
slider at the bottom to move to the left.
It's exactly what I'm talking about. Look at your browser: when you rotate the wheel down, you scroll a page down, meaning the page goes up and slider down. Graphics editors work like that too - GIMP and Inkscape. But not LibreCAD for some reason.