How to say something like "I'm sorry for misunderstanding you" in Japanese?
I want to know how I can apologize for a cultural/general misunderstanding to someone next time I see them.

For ex. I called out someone for being discriminatory for asking me if I know how to use chopsticks at a local convenient store I frequent.

There is a good chance that the Japanese woman might be xenophobic/racist, but because I need to go there often for things and see her often, I don't want things to always be awkward each time I go there.

What is the best way to say "I'm sorry for the misunderstanding" or "I'm sorry for misunderstanding you" in Japanese?

Of course, I will specify that I am talking about the last time we met by using この前.

Question

How to say something like "I'm sorry for misunderstanding you" in Japanese?
I want to know how I can apologize for a cultural/general misunderstanding to someone next time I see them.

For ex. I called out someone for being discriminatory for asking me if I know how to use chopsticks at a local convenient store I frequent.

There is a good chance that the Japanese woman might be xenophobic/racist, but because I need to go there often for things and see her often, I don't want things to always be awkward each time I go there.

What is the best way to say "I'm sorry for the misunderstanding" or "I'm sorry for misunderstanding you" in Japanese?

Of course, I will specify that I am talking about the last time we met by using この前.

Answer

I would say「この前はすみませんでした」maybe add「言い過ぎました」if you want to apologise what you said.
Like, "Sorry (for what I said) the other day. I overreacted"
I hope this helped!

Answer

I wonder if it makes sense to apologize for a misunderstanding. I mean, there are two parties in a communication going wrong, not just the receiving side. I guess it may be even embarrassing for the other, because it may imply "You did not tell it in a comprehensible way."
A proposal nevertheless: "この前、私は間違ってわかりました、すみませんでした。"