VTOL connection issue with dronekit

Hello, I have problem on communication raspberry pi to pixhawk cube orange with dronekit. When I use Q_Enable_Mode=1 (VTOL Mode) and SERIAL2_BAUD=921, LOG_BACKEND_TYPE=2 SERIAL_PROTOCOL=921 these error appear on rpi 3 ;

“from dronekit import connect
vehicle connect(”/dev/ttyUSB0", wait_ready=True, baud=921600)

raise APIException(“mode (%s, %s) not available on mavlink definition” % (m.custom_mode, m.base_mode))
APIException: mode (11, 89) not available on mavlink definition
ERROR:dronekit:Exception in message handler for HEARTBEAT
Traceback (most recent call last):
File “/usr/local/lib/python2.7/dist-packages/dronekit/init.py”, line 1531, in notify_message_listeners
fn(self, name, msg)
File “/usr/local/lib/python2.7/dist-packages/dronekit/init.py”, line 1223, in listener

dronekit = 2.9.2
pymavlink = 2.4.9
How can I overcome this issue can you help ?

Note: It doesnt come up when Q_ENABLE = 0.