Parts & Vessels Jet engines completely ignore crossfeed after any decoupler is fired (+ Ion engine always ignores crossfeed)

[DibzNr]

Reported Version: v0.2.1 (latest) | Mods: none | Can replicate without mods? Yes 
OS: Windows 11 | CPU: AMD Ryzen 5 5500 | GPU: RTX 2060 | RAM: 40GB

Severity: Medium
Frequency: 100%

Issue:
For some reason, firing any decoupler on the craft causes all jet engines to start draining from every fuel tank with methane in it, completely irrespective of crossfeed setup or fuel lines, this effect even persists through quicksaves and toggling the crossfeed option on and then off again.

In the attached video I ran an experiment using a test craft with a variety of engines including methalox, nuclear and ion engines as well as one of every jet engine, the large mk3 fuel tank they're all attached to is completely drained of fuel and the only available fuel on the craft is attached via a decoupler with crossfeed disabled, firing the 1st stage causes every engine to flameout as expected (with the odd exception of the ion engine which seems to ignore crossfeed by default, I'm unsure if this is intended behaviour but figured I'd note it here), but then firing a random decoupler suddenly causes the jet engines to spring to life as they can now draw fuel from the fuel tanks, even through the decoupler they are attached by still has crossfeed disabled on it.

Repro steps:

1. Build a craft with a jet engine, a decoupler and a methane/methalox fuel tank behind said decoupler with crossfeed disabled, then attach a 2nd decoupler anywhere on the craft
2. Launch the craft, fire the jet engine, note how it does not drain from the fuel tank behind the decoupler
3. Fire the 2nd decoupler, note how suddenly the jet engine starts drawing from the fuel tank behind the decoupler despite its crossfeed still being disabled

Video:

Spoiler

Edited March 2, 2024 by DibzNr

[Apogee-23]

I think you might need to change the color of your text. It is hard to read white on a white background.

Edited February 29, 2024 by Apogee-23