What is the correct grammatical formulation: bende or ben de?

I see it written differently everywhere. Appreciate your help

bende = ben-de = at me or on me or in me (ben + locative case suffix)

ben de = me too, I ... as well, I ...either (negative sentence)

Note that even many natives do not know how to write it correctly as use it incorectly.

Ah, tesekkurler

So "bende seni seviyorum" is incorrect?

Right! Correct one is: "ben de seni seviyorum".

Thank you!