[Unable to edit price of working order with 20 min delay]

I had a similar issue last night. I could not edit or place any orders. The error message was something like 'order cannot be completed due to price movements'. It cleared this morning but it's kind of worrying because it suggests problems lie at the server end.

[How did this SL trigger?]

Around midday yesterday, I had a SL sell on FTSE trigger at 7442.8. The 5 min candle at that time showed a High of 7440.4. That's 2.4 points from the mid price. How was that SL triggered when the B/O spread during the day is normally 2 points?

[New share dealing platform - what do you want]

A deal preview tool like they have on Tradingview. Unlike our preview, it remains on the chart so you can see where you are against the original plan. It looks a bit like the measurement tool but makes 2:1, 3:1 etc easier to see.