ROS topic /odometry disappears

Question

Im fairly new to ROS but I've never seen anything like that happen before. I'm using Raspberry Pi and ROS kinetic. After starting rosserial with:

roslaunch rosserial_server serial.launch port:=/dev/ttyACM0

and checking rostopic list this is what I get (well some of it, rest isn't important):

• /batteryState /battery_state /cmd_vel /diagnostics /diagnostics_agg /left_error /left_tick_interval /magDataArray /motor_node/parameter_descriptions /motor_node/parameter_updates /motor_power_active /motor_state /odom /odometry /right_current

After checking that I in fact have /odometry topic I run my simulation in Matlab that subscribes to odometry it runs for a few seconds and odometry stops sending messages, after I echo /odometry nothing happens an then after checking rostopic list again there is no odometry topic!

This is the list after:

• /battery_state /cmd_vel /diagnostics /diagnostics_agg /left_error /left_tick_interval /motor_node/parameter_descriptions /motor_node/parameter_updates /motor_power_active /motor_state /odom /right_current /right_error

And after checking rostopic info on odometry it says "ERROR: Unknown topic /odometry"

How can a topic disappear like that in a matter of seconds, and what could possibly be causing this?