@jiwhite @v-yujincui-msft
Thank you for the help!
Here's more info about the structure of my flow:


I am posting the message inside an "If yes" scope, and then I have another condition check that determines whether or not I will reply to the original message.
I tried the work-around with setting a messageId variable immediately after posting the message, but unfortunately it still doesn't show up in the dynamic content pane.

Just to be sure, I created some test "post message" and "reply message" blocks at outermost level, so they're not inside any conditions or other scopes, but for some reason I still don't see the messageId as dynamic content:

I checked the "peek code" settings to make sure I wasn't somehow accidentally using the deprecated actions, and it looks like the operation IDs match the new actions from the documentation:

Do you have any other suggestions for what to try? Maybe it has something to do with me updating an existing flow and not creating a new one?