IK/FK issues causing unex

I’m having trouble with IK/FK snapping in Auto-Rig Pro (not sure if this applies to all rigs), mainly due to unintended interpolation. I have auto-keying on, and when I key everything on frame 1 manually, switch to IK at frame 5 for a certain movement, then back to FK at frame 10 for a different movement, the frames between 5–10 interpolate incorrectly. When I correct them, frames 5 and 10 get altered, forcing me into a cycle of fixing and losing control of the animation.