Oh, so you can see that you are right/wrong in trot? But can’t feel/get them without looking, etc?
If so, I have a (fun? I found it fun when I made myself do it after making students do it) game for you. Your horse must listen reliably to your leg in that there can’t be a variation in length of time between when you ask for trot and when you get it. If you’ve got that, the game is as follows.
Watch and feel the outside shoulder moving forward and back in the walk. Tell yourself (out loud or in your head) that the shoulder does exactly the same in trot. It doesn’t suddenly fly off and become a whirling dervish at the first trot step. It does exactly the same it does at walk. Then, imagine yourself rising with it on the first step of trot. Then ask your horse to trot and start rising on that very first step. You’ve go a 50/50 chance of getting it right. If it’s right, congratulate yourself. If it’s wrong, tell yourself, meh 50/50, repeat the mantra of the shoulder doing the same thing in that first step of trot and try again.
Repeat. If you are consistently wrong, see what happens if you change direction. Are you now consistently right? If so, your horse may be unevenly muscled, unevenly supple, lame, or somehow otherwise uncomfortable and therefore always “helping” you to stay on one set of diagonals by virtue of the fact that one set is more comfortable to ride than the other.
At any rate, playing with this exercise can be fun, informative, and once you get both directions consistently correct, it makes your riding look fabulous and avoids those first couple of awkward sitting trot steps which makes the whole picture prettier.