Google-MySQL to BigQuery via Stitch - running into an issue (It has Public IP) still doesn't work

Followed this doc for the setting.

It tries for hostname verification and google MySQL has colon : in the host name so the hostname verification fails.
Has anyone figured out a workaround for this?

If you haven’t already, I urge you to reach out to the Stitch support team.

I have reached out to them. They don’t reply but just close the ticket in 2-3 days. So not very helpful