Hi and welcome to Just answer.
Initially, keurig 2.0 have water sensor but this sensor is electrical so it detects the water current not the specific water level. Sometimes water is the problem, if you are using distilled please stop and use filtered or bottled (not spring).
Offhand, It possibly have airlock in the pump and water intake system, remove your optional water filter if any.
Sometimes you need to get rough on your machine in able to remove the clog air on water line. slamming the water tank into machine sometimes help. If still, unplug your machine, remove water and turn the machine upside down or shake your machine if possible.
Let me know if you still have questions. Just reply before rating.
Hope this information will be helpful.
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