I think this is the part number 416402V200. I had a similar problem, which was due to the spring clip that holds the hose onto the plastic spigot that pokes out of the clutch bell-housing. In your photo, if you go to the left and up a bit from the white dot you can see the top of the clip where it sits in a groove, and should locate in a notch in the spigot. In my case, part of that clip was broken so the hose wasn't on tight.
I pulled the broken clip out, replaced the o-ring on the spigot with one from a box of assorted o-rings that cost £2-20, then used cable ties to hold the hose on nice and tight. That was last April and it hasn't leaked since. I bought some spring steel wire with the intention of bending a replacement spring clip but haven't got around to it yet. I don't think you can buy the clip on it's own, which is intensely annoying.
I think the design is poor, having that bleed valve on the hose increases the mass and means that vibration puts more stress on that retaining clip so fatigue results in it eventually breaking up. Feeding the clutch from the brake fluid reservoir isn't very clever either.
I'll attach some photos I took at the time. One shows the spigot with the hose removed, you can see the o-ring close to the tip, and further back the annular groove the clip sits in.
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