This is a known issue with the cellular module in the 2G/3G Cloud Connector. If the module does not have a defined value for the signal strength, it is set to a 300% value.
Why does it happen?
The cellular module does not give any other indication of why it in some cases is not able to provide the signal strength.
As of today, we believe that the issue is related to how the cellular module works with the cellular base stations. Such observations seem to be more common in specific locations.
You can add a filter function on your end-point filter when the signal strength value is 300%.
How can we avoid this error in the future?
The issue is related to the cellular module on the 2G/3G Cloud Connector.
DT has a plan for implementing a function to filter out these events, as they are not valid signal readings.