Nomad exec websocket: close 1000 (normal)

Hi Community,
We are facing a small issue, thought someone would have come across already, so asking here first before raising a git issue.

I get kicked out of nomad exec after 10 mins and get this error

failed to exec into task: websocket closed before receiving exit code: websocket: close 1000 (normal)

I have updated my local client version to latest

nomad -v
Nomad v1.3.5

But our the agent running on nomad cluster is still version 1.0.4. We haven’t updated our cluster yet.

I am using these params when doing exec

nomad alloc exec -e none $ALLOCATION_ID /bin/bash

Any ideas what could be going wrong here ?