Hey, the problem here seems to be the field name global used in the service definition. I could not find any ROS2 resource for this, but the ROS1 msg wiki said:
This seems to be exactly what is happening here. The ROS2 cli packages are written in python (this wasn't the case in ROS1), and global is a keyword in python. So IMO this looks like an issue in the rtabmap_ros package.