Khons G2Y portable charger: RemoteStartTransaction never answered (BootNotification/Heartbeat work fine)

[ecktisch]

Hi all,

I'm trying to get a Khons G2Y-KHONS-PE-3P-32A portable EV charger
(Vendor: Khons, Model: M3P3V3, Firmware: VA5C32D03) working with this
integration and running into a consistent issue.

What works:

• WebSocket handshake completes fine (ocpp1.6 subprotocol negotiated)
• BootNotification is received correctly with valid vendor/model/serial/firmware
• StatusNotification updates correctly (Available -> Preparing when EV is plugged in)
• Heartbeats arrive at the expected interval
• ChangeConfiguration (e.g. setting max_current) is accepted and acknowledged

What doesn't work:

• RemoteStartTransaction: sent with a valid idTag and connectorId while a
  vehicle was connected (status = "Preparing"). No response at all -
  times out after 10s ("Waited 10s for response on [...RemoteStartTransaction...]")
• GetConfiguration for specific keys (HeartbeatInterval, SupportedFeatureProfiles)
  also silently times out, while other GetConfiguration calls succeed
• Standard WebSocket ping/pong frames are not answered by the charger either,
  causing periodic disconnects until I raised websocket_ping_interval/timeout
  to 30/35s in the CS settings

So it looks like the charger implements a subset of OCPP 1.6 (enough for its
own app + basic monitoring) but doesn't respond to RemoteStartTransaction at
all - not even a CallError/rejection, just silence.

Questions for the community:

1. Has anyone else gotten a Khons charger (or a similarly rebranded/white-label
   unit) working with RemoteStartTransaction specifically?
2. Is a charger that never responds to certain Call messages (rather than
   returning a CallError) a known/common failure mode with cheaper OCPP
   implementations, or does this usually indicate a firmware bug worth
   reporting to the vendor?
3. Is there anything on the integration side I could try (e.g. a different
   OCPP version, different connectorId, etc.) before writing this off as a
   vendor firmware limitation?

I've also opened a support ticket with Khons directly, so I'll report back
if they confirm/fix it - just wanted to check if this is a known pattern
here first. Happy to share full debug logs if useful.

Thanks!