Mine does the same. About 4 mo old.
I know that some LavaTubes will reduce Voltage if the amp limit is exceeded. But at ohms (2.6~2.8ohms) that I use and the voltage I use (3.7~4.3v) I have never seen it in person.
But I have Never seen my Provari reduce Output Voltage from Displayed Voltage. It either Outputs or Errors.
I tried to vaped at a Voltage just below what would caused it to error on my Provari once. I tried High Voltages with a LR Atty once but at that wattage, the hit was so Harsh and Burnt, it was Unvapable. If I want Burnt Marshmallows, I've get a Lighter and a Coat Hanger.
And my Provari is a Version 1 which has a Lower amp limit than the Newer Version 2's.