I most definitely do not pretend to know the solution, but perhaps enable logging (see documentation) and then follow the logs to see whether the plugins are loaded correctly.
Logging should be set to the least ERROR or DEBUG to view plugin status and related errors.
I'm having a similar issue with the crowdsec middleware plugin. It turns out even when only defining the plugin in the static traefik config, it throws an error when downloading and configuring the plugin.
That needs to be resolved before you can even hope to use the middleware in the rest of your set-up.