Hi
I have the exact same problem.
Running Grafana 7.3.1 in Docker
I have setup both Telegram and Discord (without image integration) alerters
When firing the TEST button they are both good:
t=2020-11-01T12:22:08+0000 lvl=info msg="Sending telegram notification" logger=alerting.notifier.telegram chat_id=XXXXXX bot_token=XXXXXXX apiAction=sendMessage
t=2020-11-01T12:22:29+0000 lvl=info msg="Sending alert notification to" logger=alerting.notifier.discord webhook_url=https://discordapp.com/api/webhooks/XXXXXX/XXXXXX
But when the real alarms occurs, no message is sent:
t=2020-11-01T13:00:01+0000 lvl=info msg="New state change" logger=alerting.resultHandler ruleId=4 newState=ok prev state=alerting
t=2020-11-01T13:00:01+0000 lvl=info msg="Sending telegram notification" logger=alerting.notifier.telegram chat_id=XXXXX bot_token=XXXXX apiAction=sendMessage
t=2020-11-01T13:00:01+0000 lvl=eror msg="Failed to send webhook" logger=alerting.notifier.telegram error="Webhook response status 400 Bad Request" webhook="Telegram (no image)"
t=2020-11-01T13:00:01+0000 lvl=eror msg="failed to send notification" logger=alerting.notifier uid=xxxxxx error="Webhook response status 400 Bad Request"
t=2020-11-01T13:00:01+0000 lvl=eror msg="failed to send notification" logger=alerting.notifier uid=xxxxx error="Webhook response status 400 Bad Request"
Can you find similar logs ?
Regards