On step 3, the editor is still populated with the topic from step 1, but there is no indication that T1 has actually been published. It’s disconcerting because I think I may not have already published T1, so then I go look for it before “abandoning” the text that is still in the editor on step 3.
Update:
This time when I attempted to reproduce, it showed the previous topic in the editor, T0.
I think this is normal, desired behavior. Did you actually save your T1 post? If not it will remain available in composer until you do even when you click to another topic.
Repro’d here (I though I was recording with my microphone muted, so you can mute the video without missing anything):
After the video finished, I went to an incognito window and logged into Discourse to test without chrome extensions that might be causing trouble.
Here’s what happened in that new incognito session:
The very first topic I published in that session did not have the issue.
So thinking I had determined that it was an extension, I created another topic. Unfortunately, the bug cropped up again. Note that the create a new topic contents are identical to the latest post in my activity feed;