This would really annoy and upset me too Alexa
This question of thanking someone for a present applies to EVERYONE, young and old.
If I have taken the time and trouble to buy someone (friend or family) a present, or had given them money as a gift, it should be acknowledged by a 'thank you'.
I am not interested in any excuses about 'oh it's how things are these days with he young'. To not thank you is incredibly rude isn't it?
In your position I would make my feelings known to the young man, and if nothing changed then the gifts would stop, grandson or not.
Good Morning Friday 19th April 2024