I’m new to LO. I’m using a new ThinkPad with Win10 and LibreOffice is version 5.3.5. In Calc, my mouse pointer properly selects any data cell it’s pointed at. However, to select any element in any toolbar at the top of the screen, I have to position the pointer directly below the thing I want to select, but one row lower. To put this another way, the pointer is “aimed”, so to speak, one row too high. So for example if the Standard toolbar is positioned above the Formatting tool bar, then as I move my pointer from left to right along the Formatting toolbar, the various buttons in the Standard toolbar become highlighted/selected (and clicking does actuate the selected buttons). As I move my pointer along the “ABCDEFG…” row, the buttons in whatever toolbar is positioned above that row, are selected.
This behavior is the same whether I use my Logitech cordless mouse or the laptop’s touch pad (and with or w/o the mouse receiver plugged in. It’s also the same in Writer.
If I drag a toolbar to the side of the screen or detach a toolbar, then the mouse pointer’s “aim” returns to normal for that toolbar.
Also, and I have no idea whether this is related, but I don’t see what I would call a menu bar anywhere, or any way to get one to show. So, for example, I can’t find buttons for “settings” or “options” or “customization”. I do not have the program in full-screen mode.