Problems with new Instana Camunda tracing

Hello Everyone,
I am currently facing Issues with the new Camunda tracing feature from Instana. IBM Documentation

I am using the External Task Pattern and my workers can no longer access process variables. It looks like the Instana APM agents delete the process variables while requesting them from the Camunda Rest-API. Thereby my workers are missing data to function properly. Requesting them manually via Postman leads to the same result.
However, the process variables are still visible in the Camunda Cockpit and Database.

Does anyone have an idea?
Any hint is appreciated.