Beta 11 features brand-new rendering pipelines that can conflict with older graphics card drivers or improper hardware allocation. Force Dedicated GPU Usage
Confirm that the server you are playing on has TuffX installed and that you are using the most recent public beta of the client alongside the latest version of TuffX (1.2.0). If you are hosting your own server, add the TuffX plugin and restart your server for Y0 support to function correctly.
Implementing fixes for and Fancy graphics modes to prevent item-clipping when inside blocks.