not sure if ccleaner is blocked or there's a bug/
you can not see any comment at all using cc browser on youtube.
google chrome works.
did youtube block CC browser?
even logged into google youtube will not show or allow comments with CC.
it wasn't just the upgrade [89.1.8899.93] it started with the last version on 040421/
Is this still occurring? If so, can you let us know if you have any third-party extensions installed into CCleaner Browser?
Not able to reproduce this issue myself, as shown in the attached image.
As such, it would seem most likely that it's an extension issue; it's unlikely (but not impossible) that it's any of the extensions or other items in the Security & Privacy Center shipped as part of CCleaner Browser, as the screenshot was taken with all the Security & Privacy Center options enabled.
That leads me to think that it's most likely to be an incompatibility with an extension that was installed afterwards, but that's just the theory I have so far.