Your wired and wireless networks may be separated on different subnets so devices cannot see each other if they’re connected differently. On separate networks airplay uses bluetooth via P2P discovery instead of bonjour to initiate adhoc wireless network connection between devices to allow for content transfer

Can be an airplay target to allow you to cast from an iphone/ipad/mac else (depending on firmware installed) Blackb0x can possibly allow kodi to be sideloaded as a replacement interface to play media

Apps which are updated are handled by each individual itunes account. If an update is pushed it will update accordingly but minor versions may not initiate the update requiring you to login to the affected account and manually update

Get xcode and enable developer mode on the appletv