Welcome to Julia.
I am not able to reproduce your examples. Not the working one and not the error state. You have several issues in your code (e.g., port 9999 or 8888 or the "”).
Please try to give a MWE (see this https://discourse.julialang.org/t/psa-make-it-easier-to-help-you) in such a way that we just can copy paste your code to reproduce your issues.
If you think you are ready, you may check your own post with a newly opened REPL if it is really working.