Indoor drone PreArm: Need position estimate error

I am in the process of building an indoor drone. For this, I am using a UWB system (Marvelmind Superbeacons). I have set everything up, and the beacons on the drone are working. In Mission Planner, the GPS is also displayed (GPS: 3D Fix). The direction of the drone (Yaw)
is also provided by the beacons. The AltHold mode works as well. However, when I switch to Loiter or Position Hold mode, I get the message “Prearm Need Position Estimate.”

What could be causing this?

Attached are all the parameters.
parameter.param (19.4 KB)

I am not very fit with all this parameter, but if i look to your parameter file I see for example EK3_SRC1_POSXY = 3 which mean GPS not Beacon. As indoors mostly GPS is unuseable this might be a problem.
Maybe you have to configure your drone once again and I hope @amilcarlucas ardupilot methodic configurator software can help better than me

My beacons serve as GPS (and are also detected), which is why I set the parameter that way.