Can EKF Attitude to be unlocked indoor?

From the recent testment we found that if we ever fly our copter with double RTK set shown as below then there would be a EKF Attitude is bad notice as below and the aircraft would be locked.
Would there be any method to unlock this and allow a indoor flight maybe?
If there are, please do share with us, really appreciate it.

Hello, did you find the solution? I have the same problem, I use cuaw rtk-2hp. I would be happy if you share the solution.

Is your EKF primary yaw source set to “GPS”? Maybe that could be your issue.

You can set different selections of sources, and select which one depending on if you’re flying indoors or outside. EKF Source Selection and Switching — Copter documentation