OVPN would connect but no data would flow. Made suggested config script change ('comp-lzo - no' to 'comp-lzo - adaptive) and re-imported the edited script. Problem has been solved!

@phillip_mcmahon Still pretty irritated at the wast of time this has been... Before I found this thread, I spent many hours being gobsmacked at the sudden appearance of unexplained (and wrong) DHCP...