problem with station mode

[ZamesNg]

I use tello SDK 2.0 to set the tello in station mode.
then I changed the tello_addr in tello py. then I try simple_takeoff.py but it seems stuck in connect (the __send_conn_req() function in tello.py).
so could u help me to fix it?
by the way, I want to know what is the port 9617 use for? could u tell me?
thanks!!