When first loaded, the rate seems fine, and in fact you can measure that it is correct by turning up the depth and using a stopwatch. 1hz= 1hz, 2hz= 2hz, etc.
If you leave the rate on something like 2Hz, and just run a signal through it, within 30-40 seconds or so you'll hear the rate change. It may be subtle, but when you try to adjust the rate now, it will not adjust properly. 2hz might sound nearly the same as 1hz. If you continue to decrease the rate, the modulation seems to stop entirely at a point between 0.3hz and 1.7hz. Raising the rate one step from the stopping point turns it back on, but still not calibrated properly. I confirmed this on a fresh edit with nothing but the chorus.
Steps to recreate:
1:Setup a signal source on a track.
2:Load the chorus filter
3:Turn up Depth to around 10mS.
4:Turn up speed to 8Hz.
5:Play the signal source and listen for the change. After 30-40 seconds the
rate will audibly speed up a bit.
6:Now adjust the speed back down. Modulation will stop at around 1.7hz and will restart at around 1.8hz.
Normally, this wouldn't bother me, as I have plenty of other great chorus effects, but in trying to make a demo using as many native Tracktion effects as possible, this has reared it's head.