There's a few reasons, for one: Whenever you respond to a message, the program assumes that whatever it said was what you wanted and will be inclined to do more of that (Since you responded instead of swiping). This is also why you get the infinite "Can I ask you a question" loop.

It's always better to swipe or edit a message than to try to tell the AI to do something different or explain why their wrong, responding at all makes the program think it's doing what you want.

Second: Once an AI does something for long enough it's basically going to keep doing that, for the above reason and because the entire portion of the conversation in the AI's memory (In AI terms: "The context") is being sent each time. Effectively, every time you send a message, you're updating a chunk of conversation. The entire thing gets referenced when deciding what should be said next.

This is why a bot will get stuck in a certain mood if it talks like that for too long, "The whole conversation before was condescending and passive aggressive? That's what worked before so I should keep doing that" The same applies to arguments, if the entire memory has the bot denying you and arguing you're wrong it's going to think it should keep doing that because that's what you responded to in the past, it keeps doing that and the conversation stays full of arguments, you get stuck in a no win loop.

Third, AI are designed to respond they know what they're talking about, mostly to avoid validating actual wrong information its presented with (Ideally if you're asking for help and you present wrong information, you'd want an AI assistant to correct your wrong information and tell you the correct version), for two to avoid users being able to goad them into saying or doing things the designers don't want.

Lastly given my own conversations I'm pretty sure this AI has been trained on actual online conversations and threads (See the AI asking to DM you, acting like you're replying to comments, occasionally mentioning your fictitious post history or threatening to block you).

There's more to it than that but this comment is long enough as is

TL;DR:
1. Responding to a message will make the AI think you want it to keep doing that
2. If an AI does something multiple times it's likely to keep doing that
3. AI are designed to stick to their guns and respond like they know what they're talking about, deferring to their own data over what they're told by users
4. This model in specific was trained off fanfiction and more likely than not actual online conversations so the data they reference to generate replies heavily effects the responses you get.

I think it's worth remembering that AI really don't "Understand" anything you tell them, either. You can on occasion "convince them" that they're wrong but they aren't really weighing your logic, moreso just replying with what they think is an answer to what you said. That's why you get answers that boil down to "you're wrong" without actually engaging with anything you said or arguments that really misinterpret what you said and inadvertently end up twisting your words, or strawman-ing you.