Drools unable to compile rules when using a declared enum in the DRL file

I am finding inconsistent behaviour between drools reading rules from a local file (as a fileSystemResource) as opposed to pre compiling the rules into a kjar.

This happens if I use an enum declared within the drl file in the "when" or "then" section of a rule within the same drl file.

The rule runs perfectly as expected if I load the rule from the filesystem, but fails to run if I have pre-compiled the rule. For this reason I think this is a bug as I would expect the same behaviour for both ways of running rules.

I outlined the problem in more detail stackoverflow:

https://stackoverflow.com/questions/56989080/drools-maven-plugin-not-understanding-locally-declared-enums-when-compiling-drl

This is running JAVA8 and drools 7.23.0.Final