No persistent activity marking for tmux windows

[Kees de Jong]

Since a while (at least 1,5 years or so?) the persistent activity notification in tmux with powerline stopped working. Normally, when an activity happens, the tmux statusbar lits up, this still happens. But in the past this left marking for tmux windows that had an activity. This stopped working. So in other words, if you run `sleep 5s && echo` in a tmux window, then switch to another, the statusbar will light up after 5 seconds. But that window with that activity won't be marked as having an activity. Can people reproduce this? Because this is such a longstanding issue, that I start wondering that I might just misconfigured my tmux. However, I could reproduce this a few months ago in a clean VM without custom tmux/powerline configs (other than adding the powerline line in the tmux.conf).

I'm using:

$ rpm -qa tmux powerline
powerline-2.8-1.fc32.x86_64
tmux-3.0a-2.fc32.x86_64

Here is a bugreport, only one other person reported it: https://github.com/powerline/powerline/issues/2039#issuecomment-654038391