Webhooks attaching port 400 to message causing error

[thunder2k]

Server Version#: 1.15.3.876
Player Version#: 3.83.1
Hi,
I’m experiencing an issue with Webhooks.

I’ve configured them to call my join “listener” but the PMS is attaching the port 400 to the message which is causing authentication issues.

From the logs, I can see the following:
Webhook: Error delivering payload to https://joinjoaomgcd.appspot.com/_ah/api/messaging/v1/sendPush?text=plex&deviceId=MY_DEVICE_ID&apikey=MY_APY_KEY: 400

Please also note the space between : and 400

If I try to stick this URL in the browser (with or without the space between : and 400) I get the following response:

{
 "success": false,
 "errorMessage": "User Not Authenticated",
 "userAuthError": false
}

If I remove the : 400 bit, it works perfectly (actually executing the expected action) and with the following response:

{
 "success": true,
 "userAuthError": false
}

Any ideas on how I can fix this?

Thanks

Bye

Valerio