More info. It seems to only impact initial load.
I’ve had to exit chrome to reproduce again.
Navigate to Meta
Navigate to topic
Reply to Topic
Enter a line or 3 of text
Scroll to bottom quickly
Click text box to focus on reply
Navigate away from topic (latest)
Refresh page (composer should disappear)
Navigate to topic (composer restores)
Once it is fixed I can’t get it to happen without closing chrome. It seems something in the initial setup of composer is causing this. Not sure what though.