Your characters are too nice.
You can also argue, disagree (politely, rudely, friendly-rudely). You can misunderstand. You can interrupt. You can complain and ask them to get to the point. You can have the speaker fail to remember something, say something false and then correct themselves, forget the point of what they were saying and fail to answer a question, or decide they don't want to tell the listener something after all.
The listener, instead of being restricted to questions, can do what real people do: What they heard reminds them of something else, and they talk about that. "I saw that almost that same thing in Chicago, it was funny as hell. These two guys ..." And off into a story. This approach is suitable for people traveling, with nothing to do but talk. In other words, make it longer.
I think the mistake you are making is that you are trying to turn an information dump into a conversation instead, but it is just a soliloquy information dump (or history dump) from ONE character, with a prop character that is only there to prompt the next long chunk of soliloquy.
The solution is to ditch the soliloquy altogether, or if it is necessary, make it longer so the conversation develops both characters.
Remember, the reason we avoid information dumps (in exposition or dialog) is they are taxing on the reader's memory. They ask the reader to memorize a lot of stuff, and that takes them out of the story and into doing their homework.
It is seldom important for the reader to understand all at once why your character is the way they are. You need to try and engineer your story and conversation so this kind of "backstory" is not told in a big block, but in a paragraph, and preferably as an explanation for some action or decision being taken right now. If the back story never influences any action or decision, then it probably isn't important. If it does, the time to reveal it depends on how unusual it is; the less unusual, the closer the reveal can be to the decision, and vice versa. For example, if you are turning down the shrimp because shrimp gave you food poisoning as a kid, you can do that at the point of the decision.
A real conversation is not an interrogation (as you know). Bob says something. That makes Charlie think of something to talk about. That makes Bob think of something to talk about, and the conversation meanders around.
The replies are often questions IRL, but these are usually backward looking, to clarify something said, or get more information on something mentioned or claimed, they are usually NOT forward looking to lead the speaker into something entirely new.
You can make a back-and-forth conversation without any questions, and that is one way to avoid the interrogation flavor.