Portainer doesn't show icons anymore since upgrading to v2 (Traefik Proxy) - traefik

Question

Since upgrading to Portainer v2, the icons would suddenly not load anymore. I can still access Portainer (which is proxied by Traefik), but after a bit of testing, I noticed, only / would be forwarded. If a path was given, Traefik would throw a 404 error. This is a problem because Portainer loads the fonts from eg. /b15db15f746f29ffa02638cb455b8ec0.woff2.
There is one issue about this on Github, but I don't really know what to do with that information: https://github.com/portainer/portainer/issues/3706
My Traefik configuration
version: "2"
# Manage domain access to services
services:
traefik:
container_name: traefik
image: traefik
command:
- --api.dashboard=true
- --certificatesresolvers.le.acme.email=${ACME_EMAIL}
- --certificatesresolvers.le.acme.storage=acme.json
# Enable/Disable staging by commenting/uncommenting the next line
# - --certificatesresolvers.le.acme.caserver=https://acme-staging-v02.api.letsencrypt.org/directory
- --certificatesresolvers.le.acme.dnschallenge=true
- --certificatesresolvers.le.acme.dnschallenge.provider=cloudflare
- --entrypoints.http.address=:80
- --entrypoints.https.address=:443
- --global.sendAnonymousUsage
- --log.level=INFO
- --providers.docker=true
- --providers.docker.exposedbydefault=false
- --providers.docker.network=traefik_proxy
restart: always
networks:
- traefik_proxy
ports:
- "80:80"
- "443:443"
dns:
- 1.1.1.1
- 1.0.0.1
volumes:
- /var/run/docker.sock:/var/run/docker.sock:ro
- ./acme.json:/acme.json
# - ./acme-staging.json:/acme.json
environment:
CF_API_EMAIL: ${CLOUDFLARE_EMAIL}
CF_API_KEY: ${CLOUDFLARE_API_KEY}
labels:
- traefik.enable=true
- traefik.http.routers.traefik0.entrypoints=http
- traefik.http.routers.traefik0.rule=Host(`${TRAEFIK_URL}`)
- traefik.http.routers.traefik0.middlewares=to_https
- traefik.http.routers.traefik.entrypoints=https
- traefik.http.routers.traefik.rule=Host(`${TRAEFIK_URL}`)
- traefik.http.routers.traefik.middlewares=traefik_auth
- traefik.http.routers.traefik.tls=true
- traefik.http.routers.traefik.tls.certresolver=le
- traefik.http.routers.traefik.service=api#internal
# Declaring the user list
#
# Note: all dollar signs in the hash need to be doubled for escaping.
# To create user:password pair, it's possible to use this command:
# echo $(htpasswd -nb user password) | sed -e s/\\$/\\$\\$/g
- traefik.http.middlewares.traefik_auth.basicauth.users=${TRAEFIK_USERS}
# Standard middleware for other containers to use
- traefik.http.middlewares.to_https.redirectscheme.scheme=https
- traefik.http.middlewares.to_https_perm.redirectscheme.scheme=https
- traefik.http.middlewares.to_https_perm.redirectscheme.permanent=true
networks:
traefik_proxy:
external: true
And my Portainer configuration
version: "2"
# Manage docker containers
services:
portainer:
container_name: portainer
image: portainer/portainer-ce
restart: always
networks:
- traefik_proxy
volumes:
- /var/run/docker.sock:/var/run/docker.sock
- ./data/:/data/
labels:
- traefik.enable=true
- traefik.http.services.portainer.loadbalancer.server.port=9000
- traefik.http.routers.portainer0.entrypoints=http
- traefik.http.routers.portainer0.rule=Host(`${PORTAINER_URL}`)
- traefik.http.routers.portainer0.middlewares=to_https
- traefik.http.routers.portainer.entrypoints=https
- traefik.http.routers.portainer.rule=Host(`${PORTAINER_URL}`)
- traefik.http.routers.portainer.tls=true
- traefik.http.routers.portainer.tls.certresolver=le
networks:
traefik_proxy:
external: true
What do I have to change to make Traefik be able to forward the paths so that Portainer can load the icons?

Answer 1

Could you try flush your DNS Cache?
In Chrome 'chrome://net-internals/#dns' into URL bar and pressed enter.
Then click on 'Clear host cache'
Then refresh your portainer page

Answer 2

I noticed that there is also an Alpine version of Portainer.
After switching to that (image: portainer/portainer-ce:alpine), the icons seem to be working again. I don't know what the issue is with the regular image, but this solves it for now.
PS: I had tried to use the Access-Control header on Traefik, but that didn't help. I guess it's a problem with Portainer's code itself.

Answer 3

If someone else is facing this issue, I resolved this by deleting my Browser Cache or just do a full Refresh with CTRL+Shift+R