We had significant issues with Traefik not allocating or renewing certs, resulting in some painful outages. The worst part was that there was no workaround; when adding a new domain to an ingress, it was completely incomprehensible why Traefik wasn't requesting a cert, or indeed why it wasn't renewing older ones that were close to expiration. We filed GitHub issues with concrete errors, but they were never addressed. At the time, I tried to debug Traefik to understand how it worked and maybe chase down some of those bugs. I don't like to speak ill of other people's code — let's just say that peeking under the covers made me realize perfectly why Traefik was so brittle and buggy.
We eventually ditched Traefik in favour of Google Load Balancer ingresses, combined with Cert-Manager for Let's Encrypt, and this combination worked flawlessly out of the box despite not being a 1.0 release at the time. The beauty of this setup is that the control plane (cert and ingress configuration) is kept separate from the data plane (web server), so the two can be maintained and upgraded/replaced separately.