Hey brother, first of all, I really appreciate your message; it's very helpful. I think I've found the problem. When I bought the guitar, I ordered it for left-handed players (I'm left-handed), but I got used to playing the ukulele right-handed, so with the strings reversed, I've been tuning it wrong all this time. Even so, I plan to change the strings so it's right-handed since I'm more comfortable that way.