The VISQOL metric seems to be very insensitive to different AAC encoding profiles

I used HEV2 at 48 kbps, HEV2 at 64 kbps, HE at 64 kbps, HE at 96 kbps, LC at 128 kbps, and LC at 192 kbps for encoding and decoding. However, the obtained VISQOL scores are very similar. It seems that VISQOL has a very low discriminative ability for encodings with high bitrates.