504 gateway timeout when installing from Helm?

I’m trying to install Gitlab on a microk8s cluster. Everything works except gitlab itself. When I visit the configured hostname, it takes a while and then I get a 504 Gateway Timeout error. This only happens with gitlab.mydomain.com. When i visit minio.mydomain.com, I get a webpage and also registry.mydomain.com shows a valid site (though just a blank page).
When I check the services, I see that gitlab-webservice-default fails with

Readiness probe failed: Get "": dial tcp connect: connection refused
Get "": dial tcp connect: connection refused

Checking into the pods logs, I see no errors. The connections to redis and postgres are successful.

To install, I used this command:

helm uninstall gitlab -n gitlab && helm upgrade --install --wait gitlab gitlab/gitlab \
 --set global.hosts.domain=xxxxxx.com \
 --set global.hosts.externalIP= \
 --set certmanager-issuer.email=gitlab@exxxxx.com \
 --set certmanager.rbac.create=false \
 --set nginx-ingress.rbac.createRole=false \
 --set prometheus.rbac.create=false \
 --set gitlab-runner.rbac.create=false \
 --set deployment.livenessProbe.initialDelaySeconds=120 \
 --set workhorse.livenessProbe.initialDelaySeconds=120 \
 --set workhorse.readinessProbe.initialDelaySeconds=120 \
 --set deployment.readinessProbe.initialDelaySeconds=120 \
 --timeout 300s  \
 --create-namespace \
--set global.ingress.class=public \
--set nginx-ingress.enabled=false \
--set certmanager.install=false \
--set global.ingress.configureCertmanager=false \
 -n gitlab