DEF alarm keeps blaring

I hate the Cummins engine.

I will be in the middle of sleeping when the DEF light comes on and starts constantly beeping.

Then after a while driving, the big red stop engine light will come on and derate me to five mph.

I have taken the truck into the international dealership twice. Both times they replaced the same sensor but the problem returned a week later.

I took the truck to a company terminal where the mechanic said he fixed it and the problem returned less than 12 hours later.

Now I have the alarm going off again at this moment. Yes it has a full tank of def. Truck has under 20k miles on it.

Has this happened to anyone else?