Keylab 61 mk3 : arp sync with Midi clock over USB in Cubase pro 14

Hello,

Has anyone managed to get the arp to sync to Cubase’s midi clock over USB ?

I’m not talking about the Instruments’ arp (e.g. the CS-80 's internal arp : sync works fine), but the “hardware” arp on the mk3 itself.

I have Cubase set to send midi clock to 3 destinations : mk 3 MIDI and DAW ports, + a 5-pin midi interface.

In the mk3 arp settings, when choosing MIDI as my clock source, it does sync to Cubase through the 5-pin cable.
But when choosing USB, no sync (5-pin cable plugged or un plugged, same result).