unless you have a infection, sounds like you need yo calibrate your machine or ar least compare it to the drs office glucometer.
They do get off, old and need replacement. Occasionally something is wrong with the strips so it helps to use a different tube in case.
All meters including CGMs will not have exact matches. Traditional gkucometers will change with every use but the parameter of change is rather small like within 15ish mg/dl. To vary Thst widely isn’t accurate and if you are so consistently at those levels, that can be a diabetic emergency!