The errors 127 and 129 are calibration errors. They usually occur when starting the devices, but can also appear in operation.

Please restart via the toggle switch. Before you switch on the device again, this should have been switched off for about 2 minutes.
If the error persists please check whether any objects (plants, stands, cables of the cleaning staff, etc.) could disturb the device and perform another restart. The slippage of the devices by a few centimeters can, for example, cause these errors directly because the minimum distances are no longer available.

If the error persists, please contact support. See this website for contact options.