Cakewalk Rapture Session (64bit) MIDI Learn not working in Cubase Pro 9 64bit Windows 10 Pro 64 bit

Cakewalk Rapture Session (64bit) MIDI Learn not working in Cubase Pro 9 64bit Windows 10 Pro 64 bit

CC MIDI Learn not working in spite of MIDI note activity being detected by track. I am using Cubase Pro 9 64bit and an M-Audio Oxygen 49 (3rd Gen) keyboard. Keyboard side is working with plug i.e. it is receiving and transmitting MIDI fine. The fault is around MIDI learn.

The 32bit of Rapture Session version is working with the same setup in Cubase 8.5 (32bit) on the same machine so this seems to be a VST 64 bit fault. The standalone 64bit plug in is also working fine.

Any ideas what could be causing this? I have checked the MIDI filters in the Cubase Pro 9 Preferences page. I don’t have this issue with other plug ins

Many thanks in advance