The altitude hold indicator (“HÖJD” in 35J, “HÖHE” in 35OE) will blink while the autopilot is stabilizing at the current altitude when altitude hold mode has been selected. In the transsonic speed range (0.95 M to 1.1 M) the altitude hold mode will be automatically disabled, and the indicator will start blinking. Just ease off a bit on the throttle. The autopilot will enable the altitude hold function when you are out of the transsonic range.