Help with Bathroom Extractor Please

Greetings Experts
I recently bought a nice powerful (hopefully) extractor with humidistat to remove steam from the bathroom.
The fan is a Manrose MF100 and the humidistat is a Manrose 1361. The old extractor was weedy and operated on a pull cord switch (no timer or humidistat), so got left on for extended periods and is now very quiet and still.
I've tried to connect the new extractor and humidistat but they're not working as I'd expect so am looking for someone with some experience to advise if the electrical connections I've made are correct. I've used the pull cord switch which operated the old extractor.
Here's the wiring diagram which came with the humidistat:
The wiring diagram for the extractor:

Inside the pull cord switch the wiring looks like this: This is the existing switch which operated the old fan. I don't see any reason to change anything in this switch so have left it as is. So I guess the live (black wire) and neutral (grey wire) are switched. What would the brown wire in the crimp joint be for?

Inside the humidistat I've connected:
the black wire to the terminal inside the humidistat labelled "Switched live",
the grey wire to the terminal labelled "Mains Neutral", and
the brown wire to the terminal labelled "Mains Live"
Here's a photo:

Finally I've used a 2 core and earth cable to connect the extractor to the "Fan Live" and "Fan Neutral" terminals.

The Problem:
When I switch the switch on, the extractor comes on and stays on. It remains on even if I set the humidity setpoint to maximum and the timer to minimum. This evening it ran for more than an hour with the setpoint at about 95% and the run-on timer at 1 minute. I'd be surprised if the humidity in the room is really above 95%, so would expect it to run for no more than a minute.

Have I connected anything incorrectly or should I suspect the humidity sensor of being faulty?

Many thanks

The old extractor had a permanent AND switched live but no timers etc?
Strange setup..!

The browns in the crimp should be the permanent live, but you'd need to find the supply end to be certain..
depending on who installed it, the grey OR the black could be neutral.. ( don't guarantee that they are in the right holes in the pull cord.. )

Is there a setup time for the humidity stat? What do the instructions say?

Ah.. I've found the PDF..
turn the switch off..
The humidity is automatic with the switch OFF
Turning ON the switch turns on the fan which runs on for the desired time AFTER you turn the switch OFF...

First get those earth wires sleeved and connected up

Is that double pole switch your light switch or just for the humidistat/fan? (i.e. meant to be your isolator switch)

Sorry to disappoint but that's s feeble fan.

Thanks ColJack!
All your suggestions make sense. You're right, about the old extractor; it has a timer and that's given me a clue as to what's causing the new one to not work correctly. I've removed the neutral from the switch and made it into a permanent neutral by connecting through a connector block. The extractor seems to be working now. With the humidity set to 70% it turned on while I was showering and turned off again about 10 minutes after I turned the hot water off. Great!
The fan is set to it's slowest speed and is pretty effective.
Thanks all for the tips.

All that faff of a humidistat which will probably go wrong. Why not just have the fan triggered by the use of the shower?