If OSC monitor opened the UDP port 8010 on the machine, MadMapper may fail opening it (depending on how it opens the socket), so it could not receive the messages. You should stop OSC monitor and restart MadMapper to be sure that's not the reason of the issue.
Is OSC port set to 8010 in MadMapper preferences / OSC ?
OSC is working on Windows. You can even install "Bonjour for Windows" to have OSC device discovery (supported by Touch OSC for instance) - to get it search for "Bonjour Print Services for Windows" or directly here https://support.apple.com/kb/DL999?view ... cale=en_US