Static Plugin Resource returning 404

One of our customers has run into an issue where they are unable to download some static resources needed for our plugin to run. Specifically, one of the requests failing is:

BASEURL/s/en_GB/7701/5c86c3545b3c8f6447efaa8d89a83fb420d71987/1.18.2/_/download/resources/com.lucidchart.onprem.confluence.plugins.lucid-onprem-confluence:lucid-viewer-js/app/webroot/js/closure/bin/confluence-onprem/flowchart.js

This follows the format as outlined in the documentation and is generated with $webResourceManager.getStaticPluginResource in the relevant .vm file.

Our atlassian-plugin.xml is configured with the following web resource which should handle this request:

<web-resource key="lucid-viewer-js" name="Lucidchart Viewer JS"> <resource type="download" name="app/" location="app" /> </web-resource>

The customer is getting a 404. I am unable to reproduce this issue in any other enviroment I have access to. In all environments I can use, it works as expected. Even replicating all of the plugins the customer has installed I can not reproduce this issue so there doesn’t seems to be any possible conflicting plugin.

i can get a 404 by making either an incorrect PLUGIN_KEY, MODULE_KEY, or a path that does not match a resource in the associated web-resource. If I try to download a file that matches a resource and the file is not present, it returns a 500.

Has anyone run into an issue like this before and have any suggestions what else could be causing this static resource (which is present, in the right location, and I believe properly set up in the atlassian-plugin.xml) not be accessible and return a 404?

Is there maybe a reverse proxy or something in between that might be caching the 404 responses? Or maybe it’s an issue with the context path missing?