Thanks for the replies.
I did notice a wild price in the Netherlands25(40€) index on Tues 5th March 2024 at 11:30 it posted OHLC : 856, 873, 147, 849
The low of 147 (-80%) popped up at 11:30 for a very short time during a period of price outage.
It showed on my live prices, I do wonder what would have happened to an open trade during that time (I started using guaranteed stops). I guess it can happen for real occasionally.
I understand that the demo accounts are a low priority, but where this regular exchange rate noise could be coming from is strange.