What does it mean when one asks the same question but gets different answers from casting the cards? Is it a problem with my interpretation?

I think you have to trust your intuition.      each card means different things to different people.     my friend had a reading done about her relationship last year.   and when she saw the cards laid out they 'spoke' to her, she listened deeply to her intuition.   but other readers she asked saw it differently.   her intuition was correct.    doing a good intepretation requires you to study tarot books but also listening to your voice inside.     hope that answers ur question.

Do you mean that you do a new spread after the first one, and then get different cards even although the question was the same, let's say on the same day?

yes, different cards, same day, same ?, totally different answer.

well in my opinion, first of all, the chosen cards are a random result of chance. The likelihood of having the same cards again in the same position is quite small because of that. You don't get the same hand dealt to you either when playing poker. The meaning of the tarot cards is derived by the powerful serendipity... that is random events that are unrelated (pulling cards based on chance are unrelated random events) and giving meaning to them and coming to a correct conclusion because of it. If they weren't random they wouldn't be so meaningful.

People then wonder how the cards can be meaningful and correct anyway? That's the weird thing about serendipity: it always works as long as it's about trying to find understanding regarding a mystery/situation.

So, the two answers are neither of them wrong... they just shed a different light on the same issue, another point of view to understand.

Also once you came to the first answer, your own point of view shifts and is influenced by the first answer, and so your predictable behaviour is already altered.