Hello,
So here is an example to show what i'm talking about :
I have a timeline from 1 to 200.

I have a Dop Net starting at frame 100 (the start frame is set to 100 don't worry).

When i select a node that is placed before the dopnet and has an impact on that dopnet, even if i'm at frame 100 (so the start of the sim where nothing happens) or before (like frame 25), houdini will start coocking frames from 100 to 128, sometimes it'll coock 100 to 136, completely random.

It makes no sense, again i'm at frame 100 in my timeline just so that i'm at the start of the sim and it ain't wasting time coocking frames i'm not on.
I tried emptying the cache manually thinking it came from that but no.

If anyone has an explanation to that, please let me know because it drives me crazy, wasting so much time.

Hard to say what your specific issue is, but I'd argue that usually it has a reason. In the worst case you can always set your simulations to on/off (the brain icon) or the dropdown to manual update (lower right corner of Houdini). You then would have to enable it again when you need the simulation data.

It could also be, that you are inside a geometry network, but your view is set to "Show All Objects" (top right of the scene view) and this shows everything in the main obj network where data from after your sim could be linked.

Hope that helps