G7 Inaccurate Readings

I have been using the Dexcom G7 for the past two years. I know we have all experienced premature sensor failures but recently my problem has been inaccurate readings. The alarm goes off with a reading of 42. I check with a finger stick and the BG meter says 98. Eating glucose tablets or carbs does not raise the reading on the sensor. When I use the BG meter reading to recalibrate my receiver I get another error message that the calibration cannot be used. Any idea what is going on? Should I switch to the Freestyle Libre Plus 3?