Cubase 8.5 doesn't catch EQ automation

I’ve automized frequency knob on Cubase’s default channel EQ (On a drum Group), to get low-pass and hi-pass swipes.
The result is ok, but sometimes Cubase doesn’t playback the right knob positions. For example, sometimes I hear a low-pass filter effect when the knob is on 20kHz and therefore no filtering should be audible. When I switch that band off and on again, Cubase catches the automation and plays back as it should.
Any clues?