I’m not entirely sure the cause of that issue.
You can try deleting the offending key and then replacing it.
I’ve only had a similar issue happen a few times where it zooms in super super close. It took me a while to realise and I zoomed out manually and it starting working as expected.
It might happen because you are zooming into the cv on the keyframe and not the keyframe itself (select the middle of the key not the handle before zooming) but from your description it sounds like the zoom is automatic?
I say, save and post the file so we can test like Jonathan suggests.
