I am a hobby competitor for ISTD since I was in Bronze level. I am now Gold level.
Let me share something with you.

When I started in Brone I didn't have to share my dance with someone else. I always made finals but never winning. I shared my Latin with a Chinese friend she always made the finals and won i never went through to finals, when I moved up to silver level I successfully made finals in both latin and ballroom as soon as my friend joined me in the silver I never made finals but she always won. Finaly my friend went up to Gold Ballroom and stayed Silver Latin. I stayed silver in Ballroom and went up to Gold in latin. Coming first second or third. As I went up to Gold ballroom I decided not to compete until my friend went up to Gold Star, however she decided to do Gold latin. Surprisingly enough we both made finals she came second I came forth.

You are probably wondering why I am saying all this, my friend has two left feet, trips up her ballroom teacher in her finals and comes first, falls all over the place in her latin forgetting what she is doing and come second. My latin is tip top especially my jive the humiliation of my best performing dance could be beaten by someone who could not focus on her steps leads you to wonder if ISTD are a dancing school or something with no qualifications at all.

First... the ISTD is not a dance school. Secondly, judging is always ( or should be ) subjective .At the level you are in there needs to be at least 3 judges where a majority decision can be reached.

I have judged solo, but that is often in dance schools and mainly on choreod routines. Other than that, I never have been on a panel with fewer than 3 judges .

I don't know where you are competing. If you are standing up with poise and posture, using your ankles, keeping your frame the judges have to look at you. Something else is missing.

If you don't like the results you are getting, try a different instructor / studio. Don't be afraid if they take you back to basics to correct a problem. Even professional champions go back to basics as they practice. You HAVE to have a solid foundation to all dances.