If you take a bow in your hand and pull the string, and then, without releasing the RMB, select any other empty slot and select the bow again, it will be shown that the bow is selected, but it will not be in your hand and it will also be impossible to use it, the same bug occurred with the end pearl, but I did not understand exactly how to reproduce it with it
I used Google Translator to translate into English. I'm sorry if something is wrong