On habr.com, in dialogs, message scrolling does not work for everyone or just me?

Question

Habr

Hello.
Firefox 78.15.0esr
Build ID 20210927121355
Debian 10

For about a month now, I've noticed that on habr.com, message scrolling does not work in chat dialogs; the last few messages are always available and it is impossible to scroll through.
Am I the only one who has this because of some browser settings or is it like that for everyone?
I fixed it with custom css like this:

.conversation-page__body-container {
  overflow-y: scroll;
}