Issue with self signed SSL certificates

I'm not sure if this is the right place to post this so feel free to close or delete.

Basically I've been given a project to introduce a printing solution to our company and our main choice right now is using a Linux VM with Traefik.

I'll be up front right now and say I've never heard of Traefik up until now and don't have a huge amount of experience working with certificates (up until a few months ago anyway).

The issue is that I'm creating a self signed SSL certificate as instructed using openssl and then copying it over to the VM, when I reboot the VM it's supposed to authenticate it so we can access the printer portal using HTTPS and log in using our AD credentials.

Instead I'm getting the below error:

Jan 8 13:25:00 printerlogic va/config_traefik.1.7xavf6jir059vsof12447amj2[1150]: time="2021-01-08T13:25:00Z" level=error msg="Unable to append certificate (followed by a bunch of \x00\x00...)

I've attached a screenshot of part of the log, my hope is that someone can take a look and point me in the right direction. I've been working with the printer solution support team and unfortunately they don't seem to have a full fix for this issue.

It's also worth noting that it's worked once or twice in the past, but then randomly breaks and no one seems to know why. I'm hoping someone in this community may have an answer for this.

If you need more info please let me know.