Am I the only one experiencing this? I constantly got my setting rolled back to my previous setting. For example, I put a skill icon in the first box in third skill bar yesterday, and when I logged in today, it’s gone. I wrote a macro for interrupt, but I wrote “exist” instead of “exists.” I changed that, but it constantly change back to exist and display “unrecognized macro command” in the chatbox. Sometimes it happens right after I got into a dungeon. The game sometimes mess up my UI layout as well, like having the xp bar outside of my screen, unable to move the dialog box in edit mode (tried to move it to a new place but it just went back to default position when I let go my mouse), and some other UIs not in places where they were set to once or twice.
do you use a lot of addons? in my experience addons love to reset settings 
I do. I downloaded an addon pack
Unfortunately, addons are made by third parties and Blizzard does not review them for stability or issues. Any changes they make to the game that cause problems are your responsibility to troubleshoot with the makers of those addons.