We know the cause of the issue, but have yet to figure out the best solution for it. The reason this is happening is K2 is loading CBs API in way too early. K2 is loading CBs API during intializating instead of after routing.
The issue with this is the routing has not parsed the SEF URL into request variables yet. When CB is loaded we prepare our input container, which is cached with the request data. Since SEF has not parsed the URL into request data the view technically doesn't exist yet. This is why it's missing from our input container and why CB Conditional can't use it.
We have to figure out an acceptable workaround for this. I'm not yet sure where we're going to implement it, but we've a bug ticket to further investigate the issue.
forge.joomlapolis.com/issues/5340
The ticket has one proposed fix, but it's a baidaid at best and should be done much sooner. Probably needs to be fixed by our system plugin after routing.