'Kernel did not respond to kernel-info request' when using ssh session.

I'm trying to connect to my pc at work through out login node (as a jumphost). This the block config I'm using:

#+BEGIN_SRC jupyter-julia :kernel julia-1.2 :session /ssh:workpc:julia
# some code
#+END_SRC

The session is spawned correctly (after setting (setq jupyter--debug t)) the output is:

executing Jupyter-Julia code block...
jupyter-start-kernel: default-directory = /ssh:workpc:
jupyter-start-kernel: Starting process with args "/bin/python3 -c from jupyter_client.kernelapp import main; main() --kernel=julia-1.2"
Tramp: Opening connection for workpc using ssh...
Tramp: Sending command ‘exec ssh -q   -o ControlMaster=auto -o ControlPath='tramp.%C' -o ControlPersist=no -e none workpc’
Tramp: Waiting for prompts from remote shell...done
Tramp: Found remote shell prompt on ‘workpc’
Tramp: Opening connection for workpc using ssh...done
Launching julia-1.2 kernel process...done
Tramp: Inserting ‘/ssh:workpc:/run/user/10039/jupyter/kernel-0336e5aa-8bf6-4fe5-9eb0-932cdb035f11.json’...
Tramp: Encoding remote file ‘/ssh:workpc:/run/user/10039/jupyter/kernel-0336e5aa-8bf6-4fe5-9eb0-932cdb035f11.json’ with ‘base64 <%s’...done
Tramp: Decoding local file ‘/var/folders/0z/xyn859fx3vj4762qh24f8dq80000gn/T/tramp.3XGFeL.json’ with ‘base64-decode-region’...done
Tramp: Inserting ‘/ssh:workpc:/run/user/10039/jupyter/kernel-0336e5aa-8bf6-4fe5-9eb0-932cdb035f11.json’...done
SENDING: :kernel-info-request 886301a0-fe6d-4e5d-865b-b8027afa8bde nil
SENT: (:shell 886301a0-fe6d-4e5d-865b-b8027afa8bde)
Requesting kernel info...done
jupyter-kernel-info: Kernel did not respond to kernel-info request

The path to the session file is the correct one. My ssh config is:

Host A
  HostName ...
  User ...

Host workpc
  HostName ...
  ProxyJump  A
  User ...
  ProxyCommand ssh -W %h:%p A