1. “i miss my cat…” is needlessly dark/gloomy, and it’s clearly implying it’s somewhat a sore topic, that kami probably doesn’t want to ask about because it’s seen as a little rude, and kami likely doesn’t feel like/want to ask about it, so is likely ignoring that aspect of the message.
2. given the second part of the message is ignored, there isn’t really much to continue a conversation with, most kami could say is greeting you back/acknowledging what you said (which he did), or he would have to lead the conversation himself, which he likely doesn’t want to do…
…quite frankly, you have a bad-rep, there are a lot of scenarios where you’ve had rather dry/pointless or awkward/uncomfortable conversations and i’d imagine kami doesn’t want to engage with that.