Product Discovery Insights API stopped working

[Jens Schumacher - Released_so]

We’ve been using the Jira Product Discovery Insights API as documented here: https://github.com/Jira-Product-Discovery-Integrations/polaris-forge-ref-app

Unfortunately, it appears to have stopped working. We’re now receiving the following error:

(API-3500) UCT token type "OAUTH2" is not supported for this operation.

This breaks the Jira Product Discovery integration in our app and is currently impacting several customers.

Could you please advise whether this is a known issue or if there is an alternative approach we should be using? A fix or guidance would be greatly appreciated.