I am pretty sure there are 2 bugs which are related to highlights:

When you want to highlight something then you get stuck on this forever: https://prnt.sc/zssyrh . I tried once waiting for several hours and nothing happened. You cannot open highlights then in video producer, and the only way will be through your channel's main page. It is pretty recent bug and I do not know how to fix this.

Previously you could watch highlighted videos' descriptions. You can still make a description but it does not show up anymore. And old video descriptions are missing too. Many others have told about this issue too.

Would be cool if you could fix these.

Thanks in advance!