Can you elaborate on your P6015A setup, the scope manufacture and model number you are using it on, and any other details you may have?
It is very important with this probe to have an earth ground, both at the probe body and at the interface of the probe to the scope (i.e., an earth-referenced scope channel).
I also recommend reading the full user manual for this probe. Due to the typical use case of this probe (high voltage), it is important to know its limitations and requirements. The manual can be found here: https://www.tek.com/en/high-voltage-probe-manual/p6015a
