Indicators don't flash when locking car

[HPsauce]

Originally Posted by HPsauce

I now think that the interior mechanism was probably getting stuck in some interim position

I've found a possible reason for this, though I haven't yet had the latch off the car to verify.

This afternoon, to answer ainars question I had a close look at the spare latch I have - bought from A8parts last week.
I realised that it was rattling and looking closely I could see (through the hole where the release lever is) a piece of plastic moving around apparently not located onto anything.

So I popped the cover open and lifted the microswitch out, to find a small thin curved piece of nylon/plastic about 15mm by 5mm which just fell out.
Looking inside there's a long piece of the same plastic across the latch that is clearly part of the mechanism and which at the very least moves the microswitch lever.
The broken bit appeared to have come from one end, so I'm guessing it would not always work exactly as intended as it was loose and poorly located.
If the switch on my car has similar damage and loose bits in the mechanism that could explain the various failures, including non-detection of closure and not latching at all.

I've dropped A8parts an email with a photo of the parts; presumably they will be able to replace it easily enough.