Thank you so much for dedicating so much time to my problem. And also for writing such a complete guide! Simple things that are easy to misunderstand.
I followed your advice and returned to the basics: the JSON data. And it is indeed not easy to read.
After many retries, I deleted the logs, start again the container, and then export the file to my computer to read it outside of the terminal. I used visual studio code.
.... and there it was:
an error between tons of lines of "everything is fine" lines.
The error was as follow:
"level":"error","msg":"field not found, node: certresolver"
As it turns out, I had a part of the resolver label missing:
- "traefik.http.routers.traefik.certresolver=production"
It has the "tls" part missing, a simple 3 letters node.
It should have looked like this:
- "traefik.http.routers.traefik.tls.certresolver=production"
Guess what now: everything works! The dashboard, with my subdomain, and even the SSL certs are valid!
I cannot thank you enough for your help and your patience!