Do you mean some/specific zaps that appear to be missing in one client? I’d assume it’s about the relay selection, if so (but I could be wrong).

Or do you mean that one client displays zaps on all the notes, and another doesn’t? That would make sense, as it’s a decision by the developer (or possibly an option in the clients’ settings) whether to display zaps that way or not.

Want to share a screenshot or an example note ID?