Propblem running node-red with pm2 cluster mode

In my current setup, I am running node-red using pm2 in cluster mode.
When I deploy changes, I realized that only the current instance picks up the changes while other instance is still running the old version of the flow.

How can I make the other instance purge the old version of the flow and reload the new one ?

Node version : 12.16.1
Node-red : 1.0.6

Maybe you can use PM2's watch feature to run a script? Said script would, when your flow changes, copy it to the other nodes and then restart them?