981 Boxster Spyder brake / clutch fluid leak

[sfr]

I have a leak from the joint of what I believe is the brake / clutch reservoir feed to the clutch master cylinder, at the bulkhead end, not at the reservoir end.
It is the little 'corrugated' pipe that comes from the reservoir down to what I think is the clutch m/c (an audi marked piece🤷‍♂️).
From what I can gather it is only jointed by rubber olives / O rings? Does anyone have experience of replacement?
It has happened after a brake fluid change, presumable using a pressured system, by my local OPC.