** I just tried this without the curve data source and it seems to be the ope is what's glitching. Maybe it can't handle the values being updated so slowly or something? So I got it working ith a set variable event to a variable data source, with interpolation at 1 for Speed, and the interval trigger is every half a second.

So the planet is orbiting around the Sun, Albeit at 1 frame per second. Not that smooth but at least it's working.

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I have an object set to rotate 359 degrees, at a time of 8 minutes and 20 seconds. After changing the end value and or the time, it appears that if the rotation would take too long, or the ticks of the rotation are too slow, the linear datasource will simply not work.

In the following video, 359 degrees and 8 minutes 20 seconds will work, but 8 minutes 21 seconds will not work.
Also shown, 8 minutes and 20 seconds while lowering the rotation (End value) doesn't work but raising the rotation does.

So if the targeted object's movement is too slow, instead it will not move at all.

https://youtu.be/r8w_6Pv266A