High Pass Filter INCREASES Peak by 2.5dB?

[KenTheriot]

I just ran a high pass filter (80Hz) on a vocal and though the overall LUFS level was a tiny bit lower, the loudest peak INCREASED by about .5dB! Also, it became much less symmetrical, with waveform bunching up more on the top side. See pic.

Any ideas why this is?

Thanks!

[SteveG_AudioMasters_]

Your audio is far from symmetrical about zero, so I'd say that all bets are off when it comes to the algorithm that determines LUFS - which isn't the simplest thing in the world to calculate...