Very very slow update of Mavros topics

Hello There,

I am working on a rover which is equiped with a LIDAR and a SLAM. I am also using MAVROS to interface a Pixhawk 4 via TELECOM2.

What i noticed is that mavros topics such /mavros/imu/data, … are updated very very slowly, almost every second… which is problematic for all the onboard algorithms and not normal (on another setup with PX4 it is working really fast).

For information, here are the variables setup on ardurover:
SERIAL2_PROTOCOL = 1
SERIAL2_BAUD = 921
BRD_SER2_RTSCTS = 0

Do Ihvae to set up other variables?

Does anybody faced such issue before? Any hint ?

Thank you

Fabrice