It sounds like your intuitive ability, which comes to full strength during the Ascension process, is picking up something important. Ascension is often begun at the onset of the twin flame journey. That said, your intuition and gift of discernment is kicking in, in high gear right now…
Part of that twin flame journey happens to be the false aka counterfeit twin. Typically, that false twin possesses all traits of the true twin including signs, syncs and symptoms. That counterfeit twin usually presents sometime at the onset of the journey in the form of a karmic soulmate who acts as a catalyst to awaken one to that journey and process of Ascension…
It could be that your intuition has kicked in and ascension has begun and you are picking up on the fact you're dealing with a false twin. People who don't realize their false twin can spend years on the wrong direction.
There's a long path and a short path to twin flame union and I always recommend the shorter track. Had I known then what I know now, I wouldn't have wasted the better part of a year with my own false twin. This is why I advise other twins to always opt for the faster track to union.
Some may say you're simply picking up on your twin's inner work still needing to be completed, fears or other issues within them such as ego stagnation, however because twins unite in divine timing when most inner work is already completed, this is a highly unlikely theory. Plus, ego stagnation never includes being a cold-hearted person.
In your twin, you'll see yourself as a different soul part. Twins are 2 halves of the same soul incarnate in two separate human bodies. One half female energy and the other half male energy.
One will encompass one set of characteristics and traits while the other possesses the COMPLIMENTARY set. For example, one may be very logical while the other is emotional. Opposites which compliment to become one.