With my little experience on HFSS, I think you can make a simulation with a deembed. You to continu the square connector to the external like olong z axis an thenmake your port and with a deembed.
Hi tadeupasetto
There are lot of HFSS tutorials posted in this forum
You will definitely find the solution by reading the tutorials.
May be, I think you have not defined the port correctly.
Also I would recommand that place the same topic in this forum part
there are lot of experts on HFSS browsing that part.
Best of luck
ABhishekabs