I bought the BK03 in December of 2021, and so far I’ve really loved this little keyboard. However, today I noticed that some of the keys have stopped working for me, all located upperright section of the keyboard: hyphen (-), plus (+), and left curly/square bracket ([)

Are there any suggestions on what the problem might be or how to fix it? The keyboard has never gotten wet or damaged in any way. It gets daily use, otherwise, so I’m not sure if this is just something that happens from normal wear and tear.