When I select a fourth order (Highpass) LR, everything looks fine. -6dB @ 1800Hz.
After that I change it to 4th order Bessel. The graph jumps to a different target. It's -3dB @ 800Hz. Approximately.
This shouldn't be the case?
I could send you pics, but I think you can easily simulate this.
I thought you were translating the VBA. If there's something else you could 'delegate', let me know.