Cinquine

When cruise flight controller is activated, there seems to be a system which causes the plane to nosedive at high altitudes + speeds. I'm noticing it on reentry with a spaceplane, when the altitude is set to 50,000 or the vertical speed is set to something like -10, the plane will start nosediving around 55,000 m, pointing as far below the velocity vector as the craft AOA setting lets it. Then at around 25,000 it pulls up hard, and behaves normally. Is there a way to make it not do this? I've looked through all the settings and documentation (along with google searches), I can't find anything explaining this. This is with AA 1.5.6, using KSP 1.10.1 and FAR 0.16.0.1