While IG's fx spreads are quite good they have been having issues with their chart provider. Even their help desk acknowledges this, have this in writing via an email, where they quote technical difficulties.
Over the last week or two there have been observable differences between the chart price and the deal ticket price. The mid-price on the chart can be observed to be outside of the bid/ask spread and on gpb/usd alone there has been anything up to a 12 pip differential betwen the price displayed on the chart and the actual prices on the deal ticket.
It has not been unusual to observe the bars/candlesticks move in one direction and the deal ticket or the price displayed on the position screen move in opposite directions due the lag on the charts.
When trading off the charts the level of lag being experienced is unacceptable.
Have been running a screen cam on this behaviour, so that I can send it to them. Have already raised a complaint.
The lag effect on the charts has also been raised on the thread related to IG Markets.
What is interesting is that they have a known issue, but there have been no notifications issued to IG Market platform users.