I have the same problem (e.g. Sören turns into S��ren).
UPDATE:
The problem only concerns the contents in the website frame for the running apps (so the display of the apps is somewhat broken). It does not concern the header of the Shiny proxy wrapper (black header on top): When I add special characters to the header, they are displayed perfectly. Also the app overview of ShinyProxy can display those characters perfectly.
I am running ShinyProxy 3.0.1, Oracle Linux Server release 8.7, Docker version 23.0.6.
When I create my app images and start them stand-alone (individually) with “docker run”, I can test them and they look beautiful and perfect in the browser.
So the issue must have something to do with ShinyProxy.
Also, I can say that the issue first appeared when I switched from ShinyProxy 2.6.1 to ShinyProxy 3.0.1.
I am not using any templates within my folder from which I build my ShinyProxy image.
Can you reproduce?
Dockerfile:
FROM ibmjava:8-jre
RUN mkdir -p /opt/shinyproxy/
RUN wget https://www.shinyproxy.io/downloads/shinyproxy-3.0.1.jar -O /opt/shinyproxy/shinyproxy.jar
COPY application.yml /opt/shinyproxy/application.yml
WORKDIR /opt/shinyproxy/
CMD ["java", "-jar", "/opt/shinyproxy/shinyproxy.jar"]
UPDATE:
I deleted my comments on the templates as it seems this cannot be the root cause. This error seems to have nothing to do with custom templates at all.