Network issue "Couldn't find an AF_INET address for ..."

Hi!

I am trying to set up ROS to run on multiple machines. I followed the ROS Network Setup and ROS Multiple Machines guides. I can SSH from one into the other and did the netcat test which works just fine.

Machine 1 (my controller laptop)
IP: 10.5.50.167
hostname -> xps
hostname -I -> 10.5.50.167 2001:67c:10ec:5745:8000::64
I exported ROS_IP=10.5.50.167 and ROS_MASTER_URI=http://10.5.50.167:11311

Machine 2 (jetson TX2)
IP: 10.5.55.63
hostname -> jetson-dev
hostname -I -> 10.5.55.63 192.168.55.1 172.17.0.1 2001:67c:10ec:5745:8000::5a1
I exported ROS_IP=10.5.55.63 and ROS_MASTER_URI=http://10.5.50.167:11311

Procedure
- Setting up ROS_IP and ROS_MASTER_URI as described above should let me use my laptop as the master (I tried both directions, same result)
- I started the ROS master (roscore) on my laptop (Machine 1)
- On the jetson-dev I launched some nodes that publish stuff
- I can see the topics on my laptop (rostopic list), however the output (rostopic echo <topic_name>) is empty
- rostopic hz <topic_name> reports no messages are arriving
- I can ssh into the jetson from my laptop and inspect the output there succesfully using rostopic echo <topic_name>, however I would like to have it on my laptop
- Whenever I do something ROS related on the jetson-dev, I get Couldn't find an AF_INET address for [jetson-dev] in the shell on my laptop where I started the ros master via roscore

roswtf output (while having a roscore running on Machine 1
- On the laptop (Machine 1)

matt@xps:~$ roswtf
/home/matt/.local/lib/python2.7/site-packages/pkg_resources/py2_warn.py:22: UserWarning: Setuptools will stop working on Python 2
************************************************************
You are running Setuptools on Python 2, which is no longer
supported and
>>> SETUPTOOLS WILL STOP WORKING <<<
in a subsequent release (no sooner than 2020-04-20).
Please ensure you are installing
Setuptools using pip 9.x or later or pin to `setuptools<45`
in your environment.
If you have done those things and are still encountering
this message, please comment in
https://github.com/pypa/setuptools/issues/1458
about the steps that led to this unsupported combination.
************************************************************
  sys.version_info < (3,) and warnings.warn(pre + "*" * 60 + msg + "*" * 60)
Loaded plugin tf.tfwtf
No package or stack in context
================================================================================
Static checks summary:

No errors or warnings
================================================================================
Beginning tests of your ROS graph. These may take awhile...
analyzing graph...
... done analyzing graph
running graph rules...
... done running graph rules

Online checks summary:

Found 1 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected:
 * /rosout:
   * /rosout

• On the jetson (Machine 2)

  nvidia@jetson-dev:~$ roswtf
  Loaded plugin tf.tfwtf
  No package or stack in context
  ================================================================================
  Static checks summary:
  No errors or warnings
  ================================================================================
  Beginning tests of your ROS graph. These may take awhile ...