Issue with OAuth Web Server Flow - 'Sorry, there is a problem with the service'

We have successfully created an application with Companies House and generated a Web key to access the APIs.
However, when initiating the OAuth web server flow using our Client ID, we are encountering the following error: “Sorry, there is a problem with the service.”

We have reviewed similar issues discussed in the forum (URGENT - Not able to connect to the API ), but unfortunately, we have not been able to resolve the issue.

Below is the requested user authorization URL for your reference:

Could you please assist us in troubleshooting this issue?

Thank you for your help.

Hi, I have logged this issue with our IT team. I will let you know once I receive a response.