Pipewire. Disable suspend of sink

That does sound frustrating!

Assuming you’re using wireplumber alongside pipewire, you may want to try editing suspend-node.lua in /usr/share/wireplumber/scripts/node -

    -- Add a timeout source if idle for at least 5 seconds
    if new_state == "idle" or new_state == "error" then
      -- honor "session.suspend-timeout-seconds" if specified
      local timeout =
          tonumber(node.properties["session.suspend-timeout-seconds"]) or 5

      if timeout == 0 then
        return
      end

Change the 5 to 0, then restart the service and see if the issue persists?