Is it being "old-fashioned" to feel hurt when they just take the money and don't even say hello?

To be honest, we don't really interact much, but
when my maternal cousin
got married,
I wasn't able to attend the wedding.
My sibling and I are having some trouble,
and I didn't want to ruin the mood
at the venue on such a happy day, so I didn't go.
My eldest aunt lives alone and the holidays
are approaching, so I visited her house,
had a meal together, and told her
I was sorry for not being able to attend
my cousin's wedding.
I put 500,000 KRW in an envelope
and asked her to
pass it along to my cousin instead.
Since then, time has passed without a single KakaoTalk message,
so I just assumed that's how it was.
When the baby's 100th-day celebration was held near my parents' house,
the family came over to have a meal together,
and even then, I put 300,000 KRW in an envelope
and gave it to my sister-in-law.
A few months passed without any contact, so I just let it be,
but I heard they are coming to my parents' house again this weekend.
When I talked to my mother about this and asked if it wasn't
too much that they haven't even said a single hello,
she just said, "That can happen,"
but I wonder if I'm just being narrow-minded.
It's not that I gave the money to show off,
but whether it's 10 won or 100 won, I believe
it's only right to say thank you,
and that is how I have lived my life so far.
I wonder if I'm just getting older;
lately, I'm even feeling confused about my own thoughts and judgments.