I have noticed an issue with my gold volcano on Arboria. It appears that instead of erupting at 12.2kg/s for 33 seconds it erupts just once for a total of 12.2kg and then emits no further gold until the next eruption. Kind of makes the cooling setup a bit overkill.
Edit: Further investigation (I dropped the oil level for the next eruption) suggests that the volcano was marginally overpressure (where such a setup wasn't an issue elsewhere). This suggests it was over pressure but not triggering the overpressure warning.
Find and analyse a gold volcano.