How to comfort Girlfriend in long distance relationship?

tl;dr = Girlfriend doesn't feel understood and comforted in LDR

My girlfriend [19F] has communicated that she does not feel emotionally understood by me. She feels that I don't get her. She thinks I understand but on a surface level, I just hear but don't understand it.

While I understand the basic rules, like don't suggest solutions and listen without judging, I do follow them. I also say phrases like, I'm here for you but they feel too mechanical to her.

I have asked chatgpt how to improve, and I do follow them. So I wonder how to actually comfort and understand her?

P.S. Its not about sending gifts too so don't suggest that. I'm 19M