It is a huge leak in everyone's game. Nothing subtle here, just do the analysis. Order is very impotant in chess. You find the right order by looking(visualizing) both captures in a different order. Also forget about the rating it gives you. It is more important to take your time. Speed comes with practice. When you miss something, try to see why.
How to decide with which piece to take first?
Simple example you take one way with a bishop a pawn recaptures no fork, You take the other way with the knight first, with a pawn recapturing, then the bishop takes forking the king and a rook. Move order is extremely important..


for example: https://lichess.org/training/77058 i chose bb5 instead of bh6 and lost full score. why?

for example: https://lichess.org/training/77058 i chose bb5 instead of bh6 and lost full score. why?
2.Bb5?? c4 3. Ba6 c5 ( you lose dark square bishop). So Ba6 is correct.
From human point of view, there is no reason considering Bb5 as a candidate move. Bishop on b5 doesnt attack anything but risk of being attack by a4 and c4.
I wont consider Bb5 as a candidate move in my bullet.
If you have difficulty in seeing those 3 moves tactics, you can always check the solution.
Tactics training is "training to play like computer".
May I ask, if you dont know the answer from computer, what is the point of training tactics?

for example: https://lichess.org/training/77058 i chose bb5 instead of bh6 and lost full score. why?
Bb5 gives black counter attack, loses two tempo, and you lose the initiative. Bb5 c4 Ba6 c6 and you have to move the other bishop.

i Saw it more as : the Idea is to take the undefended piece and retreat to a safe square. no reason to give a full -18 score. but this is the general theme of my leaks i think. i see the Idea, but i miss the last square and blunder with this so bad :D
I see myself blundering this on tactics trainer often and i know there are probably thousands of answers, some obvious but most very subtle.
Whenever i have an obvious advantage by taking a undefended piece (or just one time defended against 2 attackers), there is always the question.. with what piece to take first.
Sometimes it is rather obvious (due to an important mating square or piece value, or an easy trap), but sometimes the solution totally eludes me as to why it is dead wrong to take with a knight instead of the bishop. I had at least full points lost on the tactics trainer by seeing the entire idea, just taking with the wrong piece (for example, take with the queen 2v1 on a knight , queen captures queen, i take queen with bishop being wrong, i had to take the knight with the bishop first but why, i was clueless, i just wanted a easy game with no queens on the board and me being up a piece, but it was not correct).

Can someone give me some primers of subtle ideas to look at when deciding with what piece to take? I think this is a huge leak in my game
Thank you very much !