Some channels name appear bold without new conten

What's happening?

Since a few days, some channels name appear in bold as if there were new content posted on it, but when I click I see no new content. Then, once the channel content has been displayed, the bold disappear as expected.

Steps to reproduce

I don't know. It seams illogical.

Relevant logs and/or screenshots

Your Environment

(Include relevant details about the environment you experienced the bug in)

• Browser name and version: Firefox 84
• Operating System and version (desktop or mobile): Ubuntu Desktop