In designer, if you select a jet fuel tank and move the slider to zero and back to full (or any other fuel amount), the jet engines will no longer work. "Zeroing" the tank is helpful to check the empty CG and full CG but this bug makes it difficult.
The jet fuel tank pictured is the fuel tank giving me trouble.
@AndrewGarrison I was trying to reproduce but best I can figure is the front inlet became occluded for some reason, no idea if this was related to the fuel tank or not, went ahead and changed all the parts and it works now, but gor now disregard this bug and if I encounter the bug again I can repost it. As always thanks to you and the rest of the devs for being so attentive :D