[bug]: SMTP not working even with correct configuration

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

I'm self-hosting a plane instance on Proxmox.
I've created the Plane instance using the script.
I've used God-Mode to configure the SMTP, however, it keeps giving me a "Network connection error. Please check your internet connection.".

I've tried multiple different configurations using SSL/TLS, but nothing works.
I did, yesterday, manage to get a single email to go though, using "https://" (either this or http) infront of the SMTP host, but I don't remember to well as it was a one time "fluke".

I do proxy this via Nginx Proxy Manager on a separate container, I have a few external facing sites.
This is the only one that has an issue.
I also tried using it via Cloudflared, but that didn't work.

My domain register is Cloudflare, the SSL cert is correctly assigned via my Nginx, and the website is not Cloudflare proxied. (that orange setting)

I've re-installed Plane 7ish times, all with different ways/configurations, I could not get SMTP to work.

Attached is an image of the web-inspector error once I get the network connection error.

As a side note, my mailbox is hosted by a smaller company, I haven't had an issue with them, but they selfhost their mail servers. (i don't think this will be an issue as I have other apps that send via SMTP without error)

Any tips would be greatly appreciated! Been working on this for like 4 hours, no avail.

Steps to reproduce

Simply configure SMTP.

Environment

Production

Browser

Google Chrome

Variant

Self-hosted

Version

vv1.9.2