The name by which channel shows on player's Home screen is determined by the name in the manifest.
Not quite sure if you meant "public" channel and which Search you were referring to.
I know if you were changing only the metadata (everything besides the bundle), you have to email dev.support to push it.
If however after renaming the channel was reviewed and published, i am baffled as to why name did not make it.
What does
https://channelstore.roku.com/ show for your channel?
You know what, just email developer at roku.com with this.