Procuria
Procuria
I can confirm this issue from @delucks. I got the same docker-setup running on Ubuntu 20.4. Please see the attached screenshot. 
I just hit the same issue. @lortonx do you propose to create a Dockerfile based project as a workroud? I'm not sure if I understood this correctly.
@IgnisDa would you be so kind to point into the direction of configuring this enhancement? What should be added into the `music: { }` part? Thank you for your good...
Had the same issue. Solution for me: 1. Remove the trailing slash in AUTHENTIK_ISSUER like in the issue @reivaxm mentioned above. 2. Setup OAuth2Provider in authentik with certificate. 
@ihatemodels thank you for the clarification. Could you point us into the direction what to setup on OpnsSense to eliminate those warnings?