Aviva 8.75% preference shares

I placed an order for some of Aviva’s 8.75% preference shares around 6pm on the 30th Sep, but this still appears under the Pending Orders tab. I’m assuming this is down to a lack of supply in the market, but does anyone else have any other reasons, or how long it takes for such an order to be executed? Thank you

@background_chocolate This security isn’t very liquid & there haven’t been any trades other than off-book since then.

Thanks David for your reply, much appreciated