We are experience this with our own web app and even the demo/template here: intersystems-community/iris-fullstack-template: This template shows you how to build, test and deploy a simple full-stack application using InterSystems IRIS REST API (github.com)
When changes are made to CSS or HTML files, we can see the changes are saved to file in the Docker container by visiting the command line. However, after refreshing, clearing cache, etc. the changes don't appear on the web application in the browser. Viewing the source css in the browser, we see it's the old file.
Had a minor success

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