That’s the expected behavior for now. If ActivityPub is enabled, it uses your Micro.blog account. But I agree ideally it should switch to cross-posting if the post you’re replying to was a reply to the Mastodon server copy of your original post.
This is all getting a little complicated. I think we may need to have a little popup menu when replying to select which account you want to use. That way the behavior would be more obvious and flexible.
Works for me. It would be better if Micro.blog automatically knows which account the original message came from, and used that.
BTW, I just checked replies on Micro.blog — Micro.blog is 21 hours behind on picking up messages from MIcro.blog.
However, for me this is not a priority feature for Micro.blog. If it stays in the current state forever, I’m OK with that — it isn’t significantly more work for me to check Masto and Bsky replies manually.
I have other items that are higher up on my Micro.blog wishlist. 