Can the wired machine cast to the Samsung TV?
I also point to Philips query as to whether the SSID is definitely not running in NAT mode (it's good to have solid confirmation of such things.)
I will be honest and say that I have issues with anything that runs Samsung versions of Android as Samsung have a habit of adding their own 'improvements' that only Samsung could ever consider an improvement, but it's what they do and they are too big to argue with.
Bitter experience has taught me to check for where Samsung they diverge from other peoples specifications (TiVo are another company do the same thing, their products don't quite behave the same as a genuine Chromecast does.)
Provided you are in Bridge mode and you have everything on the right VLANs it tends to work when using Meraki devices (*** see caviat below)
I mention the following as I haven't simply once added a ChromeCast and sent stuff to it.
The YouTube display devices I have tested so far are Chromecasts, XBox One, RPi running Android and the current model of TiVo (the small one) and the stream initiators have been Windows, Linux, Apple Mac, Android (both phones and an Raspberry Pi(s) running Linux and Android) and an iPhone.
*** However the TiVo has always been horrible, it's always visible but simply hangs about 30% of the time you send a stream to it and it's a bit worse when using a multicast reflector (fails about 60% of the time) regardless of client source, network infrastructure or method of network connection (wired or wireless.)
I did spend time setting up a 2nd VLAN and creating a multicast reflector to permit discovery and casting between VLANS them, the Chromecast worked like a dream, the TiVo was even less reliable than normal (it was visible but wouldn't actually stream the video more than 50% of the time) and the XBox One (unusually for a MS product) had absolutely no issues.