I think I can answer my own question:-
Saga PLC went through a stock consolidation 1 for every 15. The price would have been adjusted accordingly.
This is not a change by IG it's the company that's consolidated the stock.
https://www.ig.com/uk/help-and-support/spread-betting-and-cfds/market-details/what-happens-to-my-shares-position-if-the-company-performs-a-sto