Fixing Xmobar with Trayer
There is a program called Trayer that will properly reserve the space for xmobar. Trayer is originally a system tray, but we will not being using it that way (we won't see trayer at all, actually). Install trayer and Install xmobar, then open up a file called xmobarFix.sh
The text for the file should be as follows:
trayer --edge top --height 14 &
If your xmobar is configured to be on the bottom, then change --edge top to --edge bottom.
Make the file executable with chmod +x xmobarFix.sh
Lastly, copy the file to /usr/bin with sudo mv xmobarFix.sh /usr/bin/xmobarF
You can now properly launch xmobar by calling "xmobarF &" from the command line.