I'm trying to set a custom constant bit rate using the blu-ray H264 preset in AME 5.5. The max is 35 Mb/s but I've been trying to set it at 30. However, when I click OK and close the settings window, the bit rate resets to the "high" preset, which is 25. The same thing happens if I try to set the bit rate lower than the "low" preset. I'll set it for 18 and it resets to 20.74.
Here are screenshots. I tried a couple of tests and seems that the bit rate it resets to is random. For instance, I just set the bit rate to 35 and clicked OK. Then I went back into the settings and set it to 25 and clicked OK. Then I started the compression and it had reset itself back to 35. Then I deleted the source file, re-imported it, used the same blu-ray preset, and changed it to CBR 23mb/s, but when I started the encode it had jumped to 25. I stopped it, went into the settings, changed it to 18 and clicked OK. Then I went back into the settings and it was back at 25. Here are some screenshots of what's going on, taken within a couple seconds of each other.