So, I decided to finally move from ROS 2 foxy to ROS 2 galactic (I am working with Ubuntu 20.04, so no Humble for now). When I moved from one to the other I tried one package that I was developing before that was giving me some trouble in which I am simulating a DDR in Gazebo with some laser scanner and so. In the previous version (Foxy), Gazebo used to crash when I spawned to system with the spawn_entity executable. After trying a few things I decided to change from Foxy to Galactic, in case that was the problem.

After this was done, I moved quite some steps back instead of forward. Now, the robotdescription topic doesn't seem to publish the data, although the launch file runs through it and shows it, and of course is also unable to spawn the robot, since now the spawnentity service is not even receiving the robotdescription (checked with ros2 node list and the robotdescription node is not appearing), therefore it is permanently waiting.

I run through the demo nodes (Talker and receiver) and it is also not working, so it seems it is a communication issue within ROS.