Sometimes the IDE gets cranky and will not go to the definition of a function. It might jump to the declaration in the header file or it may do nothing. Sometimes compiling a project helps. Usually it is a case of closing and restarting.
Thanks for posting.
Sorry, does the 2nd sentence not explain it? I will try again. In most IDEs when "go to definition" is selected the cursor will go to the top line of the function (or other object) that is pointed to. Here if not compiled the cursor jumps to the declaration in the header file. Sometimes I find it necessary to Upload before this feature works. The worst part is if I try it before compiling it will not work after compiling either. It still just jumps to the declaration. So I must close the sketch and start over.