FT GMR Limit Order not filled & Market Making question

In my FT account, I placed a Limit order to sell 4,269 shares of $GMR @ £0.32 on 9 March.

I see on the LSE’s Trade Recap that the price went as high as £0.3221 today (3 May):

My order on FT did not fill, but I note on the market depth data on the LSE site that the block of 25K shares @ £0.3221 was trade type ‘Off-Book’.

I understand market making is algorithmic. Why wouldn’t my shares trade at my limit price, with the remainder trading at the higher price, rather than the whole block trading at the higher price? The buyer got (marginally) screwed here, and I was left unfilled.

Of course if the share price pops overnight and I get filled at a higher price, that would be great. Though it seems inherently inefficient to run the order book like this. I’m curious what I’m missing in respect to why the AIM functions this way?