Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: binary
Content-Disposition: inline
Content-Length: 407

Users have reported issues with getting the wrong option values when they have defined classes within subnet scopes.  See support issue 13886 and this thread:

https://lists.isc.org/pipermail/dhcp-users/2018-December/021500.html

I replicated the issue reported in the thread with the attached config file.

The server should emit at least a warning, if not an error when classes are defined within a scope.