Fabfilter Pro-L's meter V.S other meters?!

Hey,

I was testing a new meter VST I got (LEVELS by Mastering The Mix) and compared the output level meter to Fabfilter's meter. When I check LEVELS, the ceiling is -0.3 dB. When I check Pro-L, the ceiling is -0.2 dB. I might add that ISP detection is turned OFF on both meters. I then opened a stock dB meter from FL Studio, and also saw -0.3 dB.

Could Fabfilter be wrong? Could it be Calibrated differently?

Thank you.