I found a reddit post why sodium and potassium have 2 names:

There was some argument over what to call the elements. They were discovered by Sir Humphrey Davy who called them “sodium” from the Latin “sodanum” for a compound of sodium used as a treatment for headaches, and “potassium” from English “potash” which was the method used to extract potassium salts.

But a German chemist, Ludwig Wilhelm Gilbert, proposed “natronium” from Neo-Latin as a reference to “natron” which is what the Egyptians called sodium carbonate, and “kalium” from the Neo-Latin of the Arabic “al qalyah” which means “ashes”.

So in English they were “sodium” and “potassium”, but in German they were “Natronium” (now simply “Natrium”) and “Kalium”.

It just so happened that the guy who invented the modern chemical symbols was Jöns Jacob Berzelius. He was Swiss and spoke German, so he derived the symbols from the German names.