No, we have to force the DnsServerSearchOrder property to be an array.
Try like this
$shownet=@'
$net = get-wmiobject win32_networkadapterconfiguration
"{0}|{1}|{2}" -f @(($net | where{$_.IPaddress} | select -expandproperty IPAddress | where{$_ -notmatch ':'}),
@($net | where{$_.dnsserversearchorder} | select -expandproperty dnsserversearchorder)[0],
@($net | where{$_.dnsserversearchorder} | select -expandproperty dnsserversearchorder)[1])
'@