We know that salt is "salt" and salty is "salty."
What does the foreigner mean by "You're so salty"?
Don't translate it as "you're salty"! It's embarrassing to make a mistake.

salty
英 [ˈsɔːlti] , 美 [ˈsɔːlti]
Adjectives, meaning: salty, salty, interesting.
When used to describe people, salty means:
unhappy about something inconsequential,
By extension, "too careful, too stingy".
So the foreigner said "You're so salty", meaning
"You're angry about this, be too careful!"
【Example sentence】
1. What the hell is wrong with you? You are so salty today!
Did you take the wrong medicine today? The fire is so big.
2. Don't be salty. It's just a game.
Don't be upset, it's just a game.
Literally: the salt of the world
Actually speaks: the backbone of society, excellent people, noble people.
He was the salt of the earth and the spice of life.
He was a noble man with a great interest in life.
Literally: Worth someone's salt
Actual indication: competent and competent.
Any doctor worth his salt should be able to correctly diagnose the illness.
Any competent doctor should be able to diagnose this disease.