2 identical jwk_uri in 2 applications, but one throws "Error retrieving the client JWKSet from jwks_uri."

Hiho,

I was trying to finish up an already working implementation for SSO with Okta with a new okta account (as i wasnt able to access my old anymore, but thats another topic), so i added up in this new okta the 2 applications that I need for working, one Service API Application that allows me to sync the users, and another OIDC SSO application for allowing SSO login, both have the same jwks_uri, and the Service API is actually working fine, BUT the SSO application is throwing the error: “Error retrieving the client JWKSet from jwks_uri.” and I can’t get my head around why this can be, if the other application with the same jwks_uri just works absolute fine?

What could be reasons why I get this error, if the same URL works on another application? I also explicit copied the text field from the working app for the jwks_uri into the not working application just to be sure, but whatever I try the SSO application always throws that error. I also triple checked the client ids and everything, and i am out of ideas what i could check :D.

Thanks in advance for any hint on this!