Mupx deploy - where is Letsencrypt certificate stored?

I’ve got a meteor app that is using a Letsencrypt certificate. I deploy to a digitalocean droplet server with mupx. This has worked well in the past with other apps.

However, now I’ve got a problem. When I access the server, I get a “certificate expired” warning so I can no longer use the app.

However, when I try to update the certificate on the server, it says that it is not expired.

So does mupx store the certificate in any special place?

And not the default place, which is: /etc/letsencrypt/live/