Mattermost Grafana Integration Error: TLS handshake error remote tls bad certificate

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Summary

Integration is failing with error code:

{“level”:“error”,“ts”:1587999329.6625953,“caller”:“http/server.go:3010”,“msg”:“http: TLS handshake error from XXX.XXX.XXX.XXX:55304: remote error: tls: bad certificate”,“source”:“httpserver”}

Steps to reproduce

How can we reproduce the issue (what version are you using?)
Standard webook bot integration

Mattermost Version: 5.17.1
Database Schema Version: 5.17.0
Database: mysql

Expected behavior

Describe your issue in detail
Both servers are running SSL and both SSL certs are from Sectigo (formerly Comodo). When attempting to post a notification from Grafana to Matter most the error above is thrown, however both servers are running SSL without issue.

Observed behavior

What did you see happen? Please include relevant error messages and/or screenshots.
Fails to post notifications to channel due to the “TLS handshare error remote error tls bad certificate” error message

Could this possible be due to the CA name change from comodo to sectigo? I know that I had to manually add the CA to the java keystore on another application as it was not “known.”

Would you be open to upgrading your server? Our supported versions include v5.19 and later.